Question

Rahul can row downstream 20 km in 2 hours and upstream 4 km in 2 hours . find his speed of rowing in still water and the speed of the current .​

Answer 1

Answer :-

Rahul speed in still water = 6 Km/h

Speed of the current = 4 Km/h

Step-by-step explanation :-

GIVEN :

Rahul can row downstream 20 km in 2 hour, and upstream 4 km in 2 hours.

TO FIND :

Speed of rowing in still water and the speed of the current.

SOLUTION :

Let the speed of Rahul in still water be x Km/h and the speed of stream be y Km/h. Then we get :

Upstream = (x - y) km/h

Downstream = (x + y) km/h

Accordingly :

2(x + y) = 20 = x + y = 10 (i)

2(x - y) = 4 = x - y = 2 (ii)

Solving (i) and (ii) :

x + y = 10

x - y = 2

2x = 12

∴ x = 6

and

x + y = 10

6 + y = 10

∴ y = 4

∴,

Rahul speed in still water = 6 Km/h

Speed of the current = 4 Km/h