Question

ritu can row downstream 20 km in 2 hours and upstream 4 km in 2 hours find the speed of throwing in still water and the speed of the current?​

Answer 1

Answer:

speed of rowing in still is 6km/hr and speed of current is 4km/hr

Explanation:

Let Ritu's speed of rowing in still water be x and the speed of the current be y .

speed of Ritu while rowing

upstream = (x-y) km/hr

and downstream = (x+y) km/hr

according to given condition ,

2(x+y)=20

x+y=10 -----------(1)

2(x-y)=4

x-y=2. ------------(2)

adding equation (1) and(2)

x+y=10

x-y=2

-----------

2x=12

x=6

put x=6 in equation (1)

6+y =10

y = 4

Answer 2

Answer

speed of ritu in still water 6 km /hr

speed of ritu in stream water 4 km/he

Step-by-step explanation:

Let, Speed of Ritu in still water be x km/hr

Speed of ritu in stream water be y km/hr

Speed downstream =(x+y) km/hr

Speed upstream =(x−y) km/hr

we know,

$time = \frac{distance}{speed}$

Then

$\frac{20}{x + y} = 2$

and

$\frac{4}{x - y} = 2$

⇒ x+y=10 ...(1)

& x−y=2 ...(2)

adding both we get,

2x=12

⇒x=6

Thus using (1)

y=10−6

⇒y=4

Hence the speed of Ritu in still water is 6 km/hr and the speed of the current is 4 km/hr.