SOLUTION: Clark has a boat that can travel at 15 kph in still water. It can go 140km with the current at the same time it takes to travel 35 km against the current. What is the speed of the

Algebra ->  Rational-functions -> SOLUTION: Clark has a boat that can travel at 15 kph in still water. It can go 140km with the current at the same time it takes to travel 35 km against the current. What is the speed of the       Log On


   



Question 377467: Clark has a boat that can travel at 15 kph in still water. It can go 140km with the current at the same time it takes to travel 35 km against the current. What is the speed of the river? (Discuss how you find the solution)
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Let r = speed of current.
Then 15 - r = clark's speed against the river,
15 + r = clark's speed with the current. Then
140%2F%2815%2Br%29+=+35%2F%2815-r%29, using the formula T = D/R.
140(15-r) = 35(15 + r),
2100-140r = 525 + 35r,
1575 = 175r,
r = 9 km/hr, the speed of the river.