Question

Justin's boat travels 175 km downstream in 5 hours and it travels 189 km upstream in 7 hours. Find the speed of the boat in still water and the speed of the stream's current.

Answer 1

(V + W) * 5 = 175 boat traveling downstream

(V - W) * 7 = 189 boat traveling upstream

V + W = 35

V - W = 27

2 V = 62

V = 31 = speed of boat

2 W = 8

W = 4 speed of water

Upstream 7 * (31 - 4) = 189

Downstream 5 * (31 + 4) = 175