Question

A motor boat whose speed in still water is 18 km/hr takes 1 hour more to go 24 km upstream that to return downstream to the same spot. Find the speed of the stream.

Answer 1

Here, We have to find out the speed of stream. So we assume it as X km/h  and after that we use the condition that if speed of a boat in still water is a km/h , then speed of boat stream (a-x) km/h and speed of boat  downstream (a+X) km/h.

Now we use Time = Distance/speed and apply the condition given in the question to reach the quadratic equation.

SOLUTION IS IN THE ATTACHMENT.

Answer 2

Sb=18km/h
distance=24×2=48
Tu=Td+1
D/Su=D/Sd+1
Su=96 Ss
Ss=?
Sd=Sb+Ss
Su=Sb-Ss
Sd-Su=2Ss
Ss=Sd-Su/2
Ss=Sd-96 Ss/2
98 Ss=Sd
Sb=Sd+Su/2
2Sb=98 Ss+96 Ss
2×18=194 Ss
36/194=Ss
Ss=0.185km/h