Question

A boat covers a given distance in 6 hour moving downstream of a river. It covers the same distance in 10 hours moving upstream What would it take to cover the same distance in still water? (a) 10 hr (b) 7.5 hr (e) 5hr (d) 2'5 hr​

Answer 1

Answer:

(b) 7.5hr

Explanation:

Let velocity in still water be S

Velocity of water be W

distance to be covered be D

D=6(S+W)

D=10(S−W)

which gives S=4W

So,

D=7.5hrs.