Question

A boat traveled 225 miles each way downstream and back. The trip downstream took 9 hours. The trip back took 15 hours. What is the speed of the boat in still water? What is the speed of the current?

Answer 1

Boat = 20 mph

Current = 5 mph

Explanation:

If b is the speed of the boat, and c is the speed of the current, then:

b + c = 225 / 9 = 25

b − c = 225 / 15 = 15

Solve the system of equations with elimination.

2b = 40

b = 20

Plug back into either equation to find the speed of the current.

c = 5