Question

a motor boat whose speed 15 km/h in still water goes 30km downstream and come back in total time hit 30min find the speed of the stream

Answer 1

Let assume the speed of stream be xkm/h,
during downstream speed of boat will be (15+x)km/h,and during upstream speed will be (15-x)km/h,Now solve the equation,by using distance=speedxtime,we get equation,(30/15-x) +(30/15+x) = 1/2 hr ,after solving we find the value of x!!!