Question

Ritu can row downstream 20 km in 2 hours and upstream 4 km in 2 hours find the speed of growing in still water and the speed of current​

Answer 1

Answer:

,

Step-by-step explanation:

6 kmph is the speed at which Ritu rows 4 kmph is the speed of the current.  

Given:

Ritu downstream is 20 km in 2 hours.

Ritu upstream is 4 km in 2 hours.

To find:

Speed of rowing in still water =?

Speed of the current =?

Solution:

The speed of the rowing on still water denoted by M kmph.

The speed of the stream denoted by N kmph.

The upstream speed of Ritu’s rowing is (M – N) kmph

The downstream speed of Ritu’s rowing is (M + N) kmph

2(M+N)=20 _______________________ (1)  

2(M-N)=4 ________________________ (2)

Solving the equation, we get  

2(M+N)=20;

2(M-N)=4;  

M-N=2;

M=2+N;

Substituting M=2+N in equation (1)

2(M+N)=20

2(2+N+N)=20 ;  

N=4  

Substituting N = 4 in equation (1),  

2(M+N)=20

2(M+4)=20

2M+8=20

2M=20-8

2M=12

M=6  

the value of M = 6.

Therefore, the speed at which Ritu rows is 6 kmph and the speed of the current is 4 kmph.