Question

A motorboat can travel 30 km upstream and 28 km downstream in 7 hours it can travel 21 km upstream and written in 5s find the speed of the boat in still water and speed of the stream

Answer 1

Let the speed of boat be (x-5) in upstream and (x+5) in downstream

s=d/t ,t= d/s

30/5= 6hours

50/5= 10hours

then the equation will be

6(x+5)=10(x-5)

6x+30=10x-50

+30+50=10x-6x

80=4x

x=80/4

=20

answer is 20kmph

Answer 2

Answer:

hope the above image helps you