Question

A motorboat travels 189 kilometers in 3 hours going upstream and 475 kilometers in 5 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?

Answer 1

boat speed 79 kph

stream speed 16kph

Explanation:

Let v be the still water velocity

Let s be the stream velocity

3(v - s) = 189

3v - 3s = 189

v - s = 63

v = 63 + s

5(v + s) = 475

5v + 5s = 475

5(63 + s) + 5s = 475

315 + 5s + 5s = 475

10s = 160

s = 16 km/hr

v = 63 + 16

v = 79 km/hr