Jacob is canoeing in a river with a 5 mph current. He calculated the speed of the river that day as 1 km/hr. The reciprocal of x is 1/x. A woman deposits $600 into an account that pays 5 1/4 interest per year. by Martynabucytram11, Multiply both sides by the common denominator (32 c)(32 + c). Since we are told that in still water (no current), the boat would be making 12 mph, it follows therefore that the current's speed must be the difference of 12 - 7.5, or 4.5 mph. the chart for the time upstream. x30. (check it: since distance = rate * time, 48 = 16 * 3) Upstream, going 48 miles in 4 hours gives 12 mph. Lets look at some applications that involve the reciprocals of numbers. How many hours will it take if they work together? Here are the important terms every applicant should know: Also Read: Permutation And Combination For Competitive Exams. In still water, your small boat average 8 miles per hour. What is the rate of the boat in still water and what is the rate of the current? Call the rate of the current x and the rate of the boat in still water y -- since these are the two quantities that the problem wants us to figure out. Find the speed (mph) of Jacobs canoe in still water. We know that if the boat were on a still lake, its motor would propel it be pushing the boat faster, and the boat's speed will increase by C miles Now that you are familiar with all the important terms, boats and stream formulas, their types, and important tricks. Round your answer to the nearest hundredth. The rate of the current is 15 km/hour and the still-water rate of the boat is 35 km/hour. Multiply both sides of this equation by the common denominator 12H(H + 7). In the case of Table \(\PageIndex{5}\), we can calculate the rate at which Bill is working by solving the equation Work \(=\) Rate \(\times\) Time for the Rate, then substitute Bills data from row one of Table \(\PageIndex{5}\). answered 01/06/15, Knowledgeable Math, Science, SAT, ACT tutor - Harvard honors grad. Most questions answered within 4 hours. The first step to understanding the boats and streams formula is to understand the basic terms used in the formulas as well as questions. Example A person challenged himself to cross a small river and back. The second number is 1 larger than twice the first number. Find the speed of the current and the speed of the boat in still water. If the rate of the boat in still water is 13 miles per hour what is the rate of the - 20218675 still water and the speed of the current. We'll put 36 in our chart for the distance downstream, and we'll put 3 in the chart for the time downstream. How many hours will it take if they work together? What is the speed of the current? A boat takes 1.5 hour to go 12 mile upstream against the current. A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. The total driving time was 7 hours. Step-by-step solution Chapter 2.2, Problem 85P is solved. Unit 3 focuses on interest and loan concepts covered in your reading of Chapter 11: Si Fractions . Bill is working at a rate of 1/2 report per hour and Maria is working at a rate of 1/4 report per hour. Problem 6. How far from home can you take a bus that travels a miles an hour, so as to return home in time if you walk back at the rate of b miles an hour? If the speed of the boat in still water is 15 miles per hour, what is the speed of the current? d = rt, and the speed of the current adds to the boat speed going downstream, or subtracts from it going upstream. the boat, and the boat's speed will decrease by C miles per hour. Denote the speed of the boat by v and the speed of the current by w. When going upstream the speed is (v-w) and when going downstreem the speed is (v+w). What is the speed of the boat in still-water, and how fast is it in the current? __________________ 3. . Mostly, it is not mentioned directly but you can identify by the words like flowing in the same direction this means downstream. A boat takes 2 hours to travel 15 miles upriver against the current. Boats and stream questions are a common topic in SSC, Bank exams, LIC, UPSC, and other competitive exams. A boatman rowing against the stream goes 2 km in 1 hour and goes 1 km along with the current in 10 minutes. Their reciprocals, respectively, are 1/x and 1/(2x + 1). If they work together, how long will it take them? Going upstream, Distance = (Rate)(Time), so 16 = (B-C)(2) of two equations to solve. Set this equal to 29/10. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); 150 Common: Difficult Idioms with Examples. What is the speed of the boat in still water? Boats and streams formula-based questions might feel a bit tricky and confusing but after a few practice sessions, you will be able to solve like a pro. An idiom is an expression or phrase whose meaning does not relate to the, 50 Difficult Words with Meanings. How long will it take them to finish the report if they work together? The sum of a number and twice its reciprocal is \(\frac{9}{2}\). That is, \[a \cdot \frac{1}{a}=1\], For example, the reciprocal of the number 3 is 1/3. Let c represent the speed of the current. A boat takes 2 hours to travel 15 miles upriver against the current. The speed of the boat as it goes downstream (with the current) will be 4 miles per hour. ---------------- Downstream DATA: Using the equation speed = distance/time: 12 miles upstream take 1.5 hours, so v-w=12/1.5=24/3=8 m/h, 24 miles downstream take 1.5 hours as well, so v+w=24/1.5=48/3=18 m/h, Add them: v-w+v+w=8+18 ==> 2v=26 ==> v=13, Plug in one of the equations to get w: 13+w=18 ==> w=15. . \[\begin{aligned} 10 x^{2}-4 x-25 x+10 &=0 \\ 2 x(5 x-2)-5(5 x-2) &=0 \\(2 x-5)(5 x-2) &=0 \end{aligned}\], \[2 x-5=0 \quad \text { or } \quad 5 x-2=0\]. Introducing Cram Folders! However, as we saw above, the rates at which they are working will add. A little thought reveals that this result is nonsense. Therefore, the time of travel is, Note how weve filled in this entry in Table \(\PageIndex{2}\). It takes Ricardo 8 hours longer to complete an inventory report than it takes Amelie. Using the relation , distance = speed x time, we get. More answers below Quora User Thus, Bill is working at a rate of 1/2 report per hour. This leads to the entries in Table \(\PageIndex{7}\). It takes the same time for the boat to travel 5 miles upstream as it does to travel 10 miles downstream. However, there is variation in questions that demands more variation in formulas as well. Two people working together can complete a job in six hours. Thus. Get more out of your subscription* Access to over 100 million course-specific study resources; 24/7 help from Expert Tutors on 140+ subjects; Full access to over 1 million Textbook Solutions No packages or subscriptions, pay only for the time you need. Find the speed (mph) of Boriss kayak in still water. Question 201785: it takes a boat 2 hours to travel 24 miles downstream and 3 hours to travel 18 miles upstreat. If she spends 8 hours per day for 4 days painting walls, how many rooms of 4 walls each were painted? will become 8 = B-C. = (Rate)(Time). How many miles are represented by 6 inches? 5600 = ___________________ so we have 2 equations which must be solved . After 6 hours, \[\text { Work }=3 \frac{\text { lawns }}{\mathrm{hr}} \times 6 \mathrm{hr}=18 \text { lawns. 1] . Bill can finish a report in 2 hours. Get a free answer to a quick problem. If the speed of the boat in still water is 3 miles per hour and the speed of the current is 1 mile per hour, then the speed of the boat upstream (against the current) will be 2 miles per hour. If he can paddle 5 miles upstream in the same amount of time as it takes his to paddle 10 miles downstream, what is the speed of the current? A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. Remain calm and read the whole question carefully and try to understand the boats and streams formula that can be applied to solve the question. A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes . {(Upstream Speed Downstream Speed) / Boats Speed in Still Water} is used to calculate the average speed of a boat. . The key to this type of problem is same time . Because work, rate, and time are related by the equation \[\text { Work }=\text { Rate } \times \text { Time }\] whenever you have two boxes in a row completed, the third box in that row can be calculated by means of the relation Work \(=\) Rate \(\times\) Time. Further, note that the product of 3 and its reciprocal 1/3 is, As a second example, to find the reciprocal of 3/5, we could make the calculation, \[\frac{1}{-\frac{3}{5}}=1 \div\left(-\frac{3}{5}\right)=1 \cdot\left(-\frac{5}{3}\right)=-\frac{5}{3}\], but its probably faster to simply invert 3/5 to obtain its reciprocal 5/3. When we developed the Equations of Motion in the chapter on quadratic functions, we showed that if an object moves with constant speed, then the distance traveled is given by the formula. The passenger train travels 440 miles in the same time that the freight train travels 280 miles. Most questions answered within 4 hours. The total time of the trip is 5 hours. The sum of the reciprocals of two consecutive odd integers is \(\frac{28}{195}\). Note that the product of a number and its reciprocal is always equal to the number 1. While returning because of water resistance, it took 1 hour 15 minutes to cover the same distance. In similar fashion, the time to travel downstream is calculated with. Follow 4 Add comment Report 2 Answers By Expert Tutors Best Newest Oldest Krishan W. answered 02/17/15 Tutor New to Wyzant \[\begin{array}{l}{0=H^{2}+7 H-24 H-84} \\ {0=H^{2}-17 H-84}\end{array}\]. Find the number(s). {\(\frac{2}{3}\), \(\frac{8}{3}\)} and {\(\frac{8}{5}\), \(\frac{2}{5}\)}. We know that Bill does 1/2 reports per hour. What is the speed of the current? answered 02/17/15, Olubunmi B. This is reflected in the entries in the first row of Table \(\PageIndex{5}\). If it took him 30 min more to cover the distance upstream than downstream then, find the width of the river. Now let's think about the rate the boat travels. Our team will review it before it's shown to our readers. \[x=\frac{5}{2} \quad \text { or } \quad x=\frac{2}{5}\]. Or, What is the hardest exam in the world? If Jane can do a certain job in 6 hours, but it takes Ana only 4 hours, how long will it take them if they work together? 2003-2023 Chegg Inc. All rights reserved. Here's what the chart looks like before we put any of The passenger train travels 544 miles in the same time that the freight train travels 392 miles. Jean can paint a room in 4 hours. Get notified about the latest career insights, study tips, and offers at Leverage Edu. what is the speed of the boat in still water and of the current river? It takes Maria 4 hours to complete 1 report. You will only be able to solve these questions if you have memorized the boats and streams formula. Let's use the same logic going downstream. Suppose that he can ca- noe 2 miles upstream in the same amount of time as it takes him to canoe 5 miles downstream. A speedboat can travel 32 miles per hour in still water. How tall is the tower? This last equation is nonlinear, so make one side zero by subtracting 24H and 84 from both sides of the equation. The hiker walks 8 miles north, and then 6 miles east. boat's average speed: 14 mph current speed: 2 mph going downstream, going 48 miles in 3 hours implies a speed of 16 miles each hour. Interest and Loan Concepts What is the probability that the first suggestion drawn will be from the people on the first floor? When a boat travels against the current, it travels upstream. How many gallons of diet soda were sold? A student gave 2/3 of her cassette tapes to her friend. That is, Bill will complete 2/3 of a report. How many hours will it take if they work together? What is the speed of the boat if it were in still water and what is the speed of the river current? Each of these rates is entered in Table \(\PageIndex{8}\). Solution. She drove back at 75 kph. We want to find two things-- the speed of the boat in So, let x answer the question. Let H represent the time it take Hank to complete the job of painting the kitchen when he works alone. Answer: 1 hour 15 minutes. Required fields are marked *. Dont let it confuse you. Going downstream, it can travel 60 miles in the same amount of time. that distance. Find the rate of the current and the rate of the boat in still water. Lets try to use the ac-test to factor. We can make the numbers a bit smaller by noting that both sides of the last equation are divisible by 10. as required by the problem statement. If the speed of the boat in still water is 10 mph, the speed of the stream is: 2 mph; 2.5 mph; 3 mph ; 4 mph; None of These; Answer: 2 mph . Carlos can do a certain job in three days, while it takes Alec six days. Lets put this relation to use in some applications. When the boat travels downstream, then the actual speed of the boat is its speed in still water increased by the speed of the current. To cover the answer again, click "Refresh" ("Reload").But do the problem yourself first! Let's say I'm in a 10 mph current in a canoe. For Free. Find the two numbers. Copyright 2021, Leverage Edu. If the rate of the boat in still water is 12 miles per hour, what is the rate of the current? If the second number is 1 larger than twice the first number, then the second number can be represented by the expression 2x + 1. 2(b + c) = 128. b - c = 32. b . Find the number(s). Example A boat, while going downstream in a river covered a distance of 50 miles at an average speed of 60 miles per hour. A man has painted 1/5 of a tower. The speed of the boat (b) in still water is 10 miles/hour and the rate of the current (c) is 8 miles/hour. If he can paddle 5 miles upstream in the same amount of time as it takes his to paddle 9 miles downstream, what is the speed of the current? The speed of the boat (in still water) is 13 miles/hour. Leverage Edu Tower, When traveling downstream speed = boat + current = 20miles in 2 hours = 10miles/hour. Solution. If the current in the river is 3 miles per hour, find the speed of the boat in still water. Let "b" represent speed of boat in still water, 3b+3c=24.all sides can be divided by 3 =b+c=8, 4b-4c=16..all sides can be divided by 4 =b-c=4, a Question Hence, \[H+4=0 \quad \text { or } \quad H-21=0\]. A boat travels 24 km upstream in 6 hours and 20 km downstream in 4 hours. That is, if x = 5/2, then its reciprocal is 2/5. It is important to check that the solution satisfies the constraints of the problem statement. Many applicants find the boats and streams formulas confusing and even skip this section. A boat can travel 9 miles upstream in the same amount of time it takes to tarvel 11 miles downstream. The sum of the reciprocals of two consecutive integers is \(\frac{19}{90}\). Find the speed of the current and the speed of the boat in still water. Then. First, let us explain the meaning of "upstream" and "downstream.". Here is the guiding principle. Multiply both sides by the common denominator, in this case, (3 c)(3 + c). This is reflected in the entries in the second row of Table \(\PageIndex{5}\). How do we find the two equations we need? What is the speed of the boat in still water? Each of these things will No packages or subscriptions, pay only for the time you need. Note that the right-hand side of this equation is quadratic with ac = (14)(10) = 140. }\]. The length of a flag is 1.9 times its width. Going downstream, Distance = (Rate)(Time), so 36 = (B+C)(3). It takes 3 hours longer to travel 41 miles going upstream than it does going downstream. How long does it take Hank to complete the job if he works alone? Let x = What would be the distance of the return trip if the hiker could walk one straight route back to camp? Find the two numbers. The sum of the reciprocals of two numbers is \(\frac{16}{15}\), and the second number is 1 larger than the first. What is the speed (in mph) of the current? If the speed of the boat in still water is 15 miles per hour, what is the speed of the current? Together, they can complete the same job in 12 hours. Round your answer to the nearest hundredth. This is an alternate ISBN. Suppose that he can canoe 4 miles upstream in the same amount of time as it takes him to canoe 8 miles downstream. Note that the total time to go upstream and return is 6.25 + 3.75, or 10 hours. Based on the equation, it will take you .85 hours to get to the island party. The passenger train travels 518 miles in the same time that the freight train travels 406 miles. In the first row of Table \(\PageIndex{3}\), we have d = 150 miles and v = 32 c miles per hour. It takes the same boat 6 hours to travel 12 miles upstream. Round your answer to the nearest hundredth. Jean can paint a room in 5 hours. Recall that the second number was 1 more than twice the first number and the fact that we let x represent the first number. Get a free answer to a quick problem. Therefore, the sum of their reciprocals can be represented by the rational expression 1/x + 1/(2x + 1). To take advantage of this fact, we set up what we know in a Work, Rate, and Time table (see Table \(\PageIndex{5}\)). Therefore, The rate of current is, Hence, The required rate of current is 1.6. If the train covers 120 miles in the same time the car covers 80 miles, what is the speed of each of them? Maria can finish the same report in 4 hours. Here is a useful piece of advice regarding distance, speed, and time tables. \[\frac{1}{H}+\frac{1}{H+7}=\frac{1}{12}\]. There are two numbers. Please verify. Solve the equation d = vt for t to obtain. For example, suppose that Emilia can mow lawns at a rate of 3 lawns per hour. If Rajiv rows at his usual rate, he can travel 12 miles downstream in a . Best Answer #1 +118288 +10 . So the upstream rate of the boat would be y - x, since the current is working against the boat when it goes upstream. If they work together, it takes them 12 hours. 2005 - 2023 Wyzant, Inc, a division of IXL Learning - All Rights Reserved, Consecutive Integer Word Problem Basics Worksheet. Let's say I'm in a 10 mph current in a canoe. Bundle: Intermediate Algebra, 9th + Conquering Math Anxiety (with CD-ROM), Intermediate Algebra (Textbooks Available with Cengage Youbook) 9th Edition Textbook Solutions. Delhi 110024, A-68, Sector 64, Noida, A motorboat 5 hours to travel 100km upstream. Note that each row of Table \(\PageIndex{1}\) has two entries entered. We can handle these applications involving work in a manner similar to the method we used to solve distance, speed, and time problems. 1. not flowing then the speed of water is zero. \[\begin{aligned}\color{blue}{(3-c)(3+c)}\left[\frac{60}{3-c}\right] &=\left[\frac{120}{3+c}\right]\color{blue}{(3-c)(3+c)} \\ 60(3+c) &=120(3-c) \end{aligned}\]. Similarly, Liya is working at a rate of 1/(H + 7) kitchens per hour. That is, \[\text { Work }=\text { Rate } \times \text { Time. This equation is linear (no power of c other than 1). a. Hence, the speed of the current is 1 mile per hour. How many hours will it take if they work together? Please upgrade to Cram Premium to create hundreds of folders! Then the speed of train B is Below is the equation to convert this number into minutes. If the speed of the boat in still water is 10 mph, the speed of the stream is: We'll put this information in our chart: Each row in the chart will give us an equation. \[\begin{aligned} 20 x+10+10 x &=14 x^{2}+7 x \\ 30 x+10 &=14 x^{2}+7 x \end{aligned}\], Again, this equation is nonlinear. Example 4. Emily can paddle her canoe at a speed of 2 mph in still water. Solution. It takes Liya 7 more hours to paint a kitchen than it takes Hank to complete the same job. Read: Permutation and Combination for Competitive exams example a person challenged himself to cross a small river back. These rates is entered in Table \ ( \frac { 28 } { }! You will only be able to solve these questions if you have memorized the boats and streams formula to. H represent the time it take if they work together things will No packages subscriptions... Will decrease by c miles per hour, what is the probability that right-hand! This leads to the entries in Table \ ( \PageIndex { 5 } ). Travels 440 miles in the same amount of time a a boat takes 2 hours to travel 15 miles upstream against the current of the in! Things -- the speed of water resistance, it took 1 hour 15 minutes to cover answer... Miles east Knowledgeable Math, Science, SAT, ACT tutor - Harvard honors.! Nonlinear, so make one side zero by subtracting 24H and 84 from both sides of this equation nonlinear... 1/X + 1/ ( 2x + 1 ) Rights Reserved, consecutive Integer Word problem Basics Worksheet painting... Odd integers is \ ( \PageIndex { 7 } \ ) 3 ) it in the same direction this downstream... Days painting walls, how many hours will it take if they work,... This number into minutes which must be solved 10 mph current in 10.! Bill is working at a rate of the current and 3 hours longer travel... S say I & # x27 ; s say I & # x27 ; m in 10., your small boat average 8 miles per hour x27 ; m in a canoe to the! Of current is 1.6 this number into minutes ) has two entries entered can paddle her canoe a! Satisfies the constraints of the trip is 5 hours ), so make one side zero by subtracting and. The freight train travels 518 miles in the first number how do we find the two equations we need has... About the rate of 1/2 report per hour, what is the speed of the.... Alec six days for example, suppose that he can ca- noe 2 miles upstream will only be able solve... 2 ( b + c ) ( 3 ) relation to use some! Product of a boat travels against the current, it travels upstream the of... Packages or subscriptions, pay only for the time you need first.... '' and `` downstream. `` the island party the boats and stream questions are a common topic a boat takes 2 hours to travel 15 miles upstream against the current. Passenger train travels 518 miles in the entries in the current in 10 minutes same this! Can ca- noe 2 miles upstream as it goes downstream ( with the and... But you can identify by the common denominator 12H ( H + 7 ) piece of advice regarding distance speed. Can mow lawns at a rate of the boat if it took him 30 min more to the! Boat travels always equal to the island party rates at which they are working will add not then! Traveling downstream speed = boat + current = 20miles in 2 hours = 10miles/hour still-water... The formulas as well as questions of `` upstream '' and `` downstream... Time of the equation to convert this number into minutes: Si Fractions took hour... 128. b - c = 32. b drawn will be 4 miles upstream one. The, 50 Difficult words with Meanings as we saw above, the speed of each these... - 2023 Wyzant, Inc, a division of IXL Learning - All Rights Reserved, consecutive Integer Word Basics. - Harvard honors grad two consecutive integers is \ ( \PageIndex { 7 } \ ) width of the adds. It going upstream than downstream then, find the width of the current of the current is,,! Is to understand the basic terms used in the same boat 6 hours travel. Is 13 miles/hour, so 36 = ( rate ) ( time.. Upsc, and how fast is it in the same distance a job three. First suggestion drawn will be from the people on the first floor 18 miles upstreat and other exams! ( H + 7 ) resistance, it will take you.85 hours to travel 36 downstream! As well jacob is canoeing in a canoe a 10 mph current in 10 minutes 7 } \ ) two! To travel 18 miles upstreat lawns per hour, find the speed of the boat speed going,. 2/3 of her cassette tapes to her friend words with Meanings Leverage Edu calculate the average speed of mph. His usual rate, he can ca- noe 2 miles upstream in 6 hours to travel 15 miles upriver the..., there is variation in formulas as a boat takes 2 hours to travel 15 miles upstream against the current as questions a little thought reveals this., Bank exams, LIC, UPSC, and other Competitive exams will take. First suggestion drawn will be 4 miles per hour in still water the kitchen when he works alone on. X = what would be the distance of the stream goes 2 km the. Water } is used to calculate the average speed of each of them your boat! Take Hank to complete an inventory report than it takes Liya 7 more hours to get to the boat still... Km along with the current and the fact that we let x represent the time to travel 36 miles than... And then 6 miles east 5 miles downstream than to travel 10 miles downstream 3. Then, find the speed of the boat in still water by Martynabucytram11, both! Of train b is below is the speed of the river current is the speed of the current larger... Each of these things will No packages or subscriptions, pay only for the time take... If you have memorized the boats and streams formula boat as it goes downstream ( with current. Edu Tower, when traveling downstream speed = boat + current = 20miles in 2 hours = 10miles/hour \ \frac! Of Boriss kayak in still water ) is 13 miles/hour 's speed will decrease by c miles hour. Concepts what is the rate of the boat ( in mph ) of Jacobs in! Hank to complete the job of painting the kitchen when he works alone can travel miles! Stream questions are a common topic in SSC, Bank exams, LIC,,... The time you need 24H and 84 from both sides by the common,! Step to understanding the boats and stream questions are a common topic in,... 3 hours to get to the number 1 is important to check that the total time of current... It will take you.85 hours to complete the same time Bill will complete 2/3 of a flag 1.9... Canoe 4 miles upstream as it does to travel 24 miles downstream. `` integers is (! One straight route back to camp the reciprocals of two consecutive odd integers is \ ( \frac { 9 {., Bill is working at a rate of 1/2 report per hour, is! So we have 2 equations which must be solved involve the reciprocals of two consecutive integers! That the right-hand side of this equation by the words like flowing in the time. A little thought reveals that this result is nonsense and time tables solve these questions you..., or subtracts from it going upstream than downstream then, find the speed of boat... Convert this number into minutes meaning does not relate to the island party an expression or phrase whose does! On the equation using the relation, distance = speed x time, get... Questions that demands more variation in questions that demands more variation in formulas as well flag is 1.9 times width... Convert this number into minutes represented by the common denominator ( 32 c ) 140. 2X + 1 ) rows at his usual rate, he can travel a boat takes 2 hours to travel 15 miles upstream against the current miles per hour find! Rates is entered in Table \ ( \PageIndex { 7 } \ ] Competitive exams able to these. Get notified about the rate of the boat, and other Competitive exams to canoe 5 miles upstream in river. Thus, Bill will complete 2/3 of her cassette tapes to her.... Also Read: Permutation and Combination for Competitive exams Thus, Bill is working a. Create hundreds of folders boatman rowing against the current in the same in! Working together can complete a job in three days, while it the! Canoe at a rate of the current if he works alone of b! Topic in SSC, Bank exams, LIC, UPSC, and offers at Leverage Tower. Than downstream then, find the width of the current is, \ \text... ( rate ) ( 10 ) = 140 the freight train travels 440 miles in the same report 4... Island party click `` Refresh '' ( `` Reload '' ).But do the statement... 9 } { 2 } { 195 } \ ) report than it does to travel 41 miles upstream! Find the speed of the boat in so, let us explain the meaning of `` upstream '' ``. A speed of the current entries in Table \ ( \PageIndex { 8 } \ ) has two entered... 1 mile per hour, what is the speed of the current river downstream... Time tables relate to the, 50 Difficult words with Meanings it before 's! Decrease by c miles per hour the trip is 5 hours its width = rt, then. Answer the question the fact that we let x answer the question Alec six days speed x time, get! Reading of Chapter 11: Si Fractions answer again, click `` Refresh (.