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?

 

Let the speed of sailor in still water be x km/hr and the speed of stream be y km/hr.

The speed of boat (upstream) = (x - y) km/hr.

The speed of boat (downstream) = (x + y) km/hr.

Now,

A.T.Q.

(1) 8 / x + y = 40 / 60 (Since, Time = Distance / Speed)

===> x + y = 12 ----------------- (1)

(2) 8/ x - y = 1 (Since, Time = Distance / Speed)

===> x - y = 8 ------------------- (2)

On adding (1) and (2),

===> x + y + x - y = 12 + 8

===> 2 x = 20

===> x = 10

By (1),

===> 10 + y = 12

===> y = 2

Ans :- The speed of sailor in still water is 10 km / hr.

The speed of stream is 2 km / hr.

  • 126

thanx a lot!!!

  • 4
 

 

Let the speed of sailor in still water be x km/hr and the speed of stream be y km/hr.

The speed of boat (upstream) = (x - y) km/hr.

The speed of boat (downstream) = (x + y) km/hr.

Now,

A.T.Q.

(1) 8 / x + y = 40 / 60 (Since, Time = Distance / Speed)

===> x + y = 12 ----------------- (1)

(2) 8/ x - y = 1 (Since, Time = Distance / Speed)

===> x - y = 8 ------------------- (2)

On adding (1) and (2),

===> x + y + x - y = 12 + 8

===> 2 x = 20

===> x = 10

By (1),

===> 10 + y = 12

===> y = 2

Ans :- The speed of sailor in still water is 10 km / hr.

The speed of stream is 2 km / hr.

  • 18

right ans by blue star.

  • -6

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

  • -6

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.

  • 10

hey thx to u all and stop fighting here and

and......  djani ARCobat wht happen if she copied answer any problem to you and by the way wht the problem 

Is it so dangerous tht u have wriiten here dont tell to anybody

if u are telling tht means u have lack of Moral Values 

i will just say tht much only thx

  • 6
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