Question

a boat travels 30 km upstream in a river in the same period of time as it takes to travel 50 km downstream. if the rate of stream be 5 kmph , find the speed of the boat in still water.

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:

Step-by-step explanation:

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

=20kmph