Question

Raj travels 30 km upstream. If his speed in still water is decreased by 2 and speed of stream is incresed by 2 his time of joirney would increase by 10 hours calculate the speed of stream

Answer 1

Let speed of raj in still water be x
Original speed of stream be y
Now accto ques
New speed in still water is x-2
New speed of stream is y+2
Speed when going up stream is x-2-(y+2)=x-y-4
Initialy time taken is 30/x-y
Final time taken increases by 10 hours that is 30/x-y +10=30/x-y-4
Put values and solve