Math, asked by aishwarya1995, 1 year ago

the speed of a motorboat in still water to that of the current of water in the river are in the ratio 7:2. If the motorboat takes 3hrs 54mins to go to a certain distance in upstream, how long will it take to fo the same distance in downstream?​

Answers

Answered by zahabm9898
0

Answer:

Step-by-step explanation:

Let x = speed of boat in still water

Let y = speed of the current

then

(x+y) = speed with the current

and

(x-y) = speed against the current

:

Write a distance equation for each trip: Dist = time * speed

;

2(x + y) = 50

3(x - y) = 45

;

Simplify divide the 1st equation by 2 and the 2nd equation by 3; results:x + y = 25

x - y = 15

------------addition eliminates y, find x

2x = 40

x = 40%2F2

x = 20 mph speed of boat in still water

:

Find y using; x + y = 25

20 + y = 25

y = 25 - 20

y = 5 mph speed of the river

:

:

Check solutions in the 2nd original equation

3(x - y) = 45

3(20-5) = 45

3(15) = 45;

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