Question

the speed of a boat in still water is 15 kilometre per hour and the speed of a stream is 5 kilometre per hour find the time taken by the board to cover 40 km upstream ​

Answer 1

Answer: 4 hours

Explanation:

distance (d) = [rate (r) - current (c)] × time (t)

Given: d = 40, r = 15, c = 5

40 = (15 - 5)t

40 = 10t

4 = t