Question

A motor goes down stream 30 km and again return to the starting point in a total time of 4 hour 30minutes .if the speed of the boat is 15 km/h in still water. Find the speed of the stream?

Answer 1

Answer:

Step-by-step explanation:

downstream speed=speed of boat+speed of stream

u+v=15+v

distance/speed=time

(30/(15+v))+(30/(15-v))=4+(1/2)

30(15-v)+30(15+v)=9*(225-v^2)/2

450-30v+450+30v=9(225-v^2)/2

900*2=9(225-v^2)

200=225-v^2

v^2=25

v=5