Question

A person can row 18 km downstream and 12 km upstream in 3 hours also we can draw 36 km downstream and 40 km upstream 8 hours find the speed of going in still water and also the speed of stream by making the pair of linear equation for the

Answer 1

speed of boat= 10km/hr
speed of stream=2 km/hr

Answer 2

Answer:

Hence the speed of person is 10 km /hr and speed of river is 2 km/hr.

Given:

A person can row 18 km downstream and 12 km upstream in 3 hours also we can draw 36 km downstream and 40 km upstream 8 hours

To Find:

Find the speed of person and speed of the river.

Step-by-step explanation:

Let the speed of person in still water =  x km/hr

Let the speed of the river = y km /hr

upstream speed , u= x-y

downstream speed , v= x+y

according to question,

A person can row 18 km downstream and 12 km upstream in 3 hours,

18/v +12/u = 3 ..................(1)

He can draw 36 km downstream and 40 km upstream 8 hours

36/v + 40/u = 8.................(2)

Solving equation 1 and equation 2

we get , 1/v = 1/12

v=12 km /hr

x + y = 12 ........................(3)

1/u = 1/8

u= 8 km/hr

x - y = 8 ...........................(4)

Solving equation 3 and equation 4

x = 10 , y =2

Hence the speed of person is 10 km /hr and speed of river is 2 km/hr.