A sailor goes 8 km downstream in 40 minutes and returns in 1 hour.Determine the speed of the sailor in still water and the speed of the current?

thanx a lot!!!

right ans by blue star.

you shameless bluestar... you are always copying answers of other from either meritnation or yahoo answers

Let the speed of sailor in still water and the speed of stream be x km/h

and y km/h respectively.

Speed of Ritu while rowing

Upstream = (x-y) km/h

Downstream = (x+y) km/h

According to question, 

1)40/60*(x+y)=8.

2/3*(x+y) = 8……..(x3)

2(x+y)= 24

X+y=12 --------1

2)1x-y=8

X-y=8----------2

Adding equation (1) and (2), we obtain

X+y  +  x-y = 12+8

2x=20, x = 10.

Putting this in equation (1), we obtain

y+10 =12.

Y = 2.

Hence, the speed of sailor in still water is 10 km/hr [x]

Speed of the current (stream) flow is 2km/hr [y]

hope u understood.