Question

a boy walks from his house to his school if he walks at a speed of 21/2 kilometre per hour he is hero hi school in 30 minute how far is the school from his house​

Answer 1

Answer:

ANSWER

Let the distance between the home & the school of the boy = x km.

In the first case, the speed is 2

2

1

km/hr =

2

5

km/hr.

∴ Time taken = x÷

2

5

hr.

=

5

2x

hr.

In the second case his speed= 1 +

2

3

km/hr. =

2

7

km/hr.

∴ Time taken=x÷

2

7

hr.=

7

2x

hr.

∴ The difference in time = (

5

2x

−

7

2x

)hr.=

35

4x

hr.=

35

4x

×60min.=

7

48x

×min.

Now , in the first case he is 6 min late = −6 min. and

In the second case, he is 6 min early = +6 min.

∴ The difference in time=[6−(−6)]min.=12 min.

∴

7

48x

min.=12 min.

Or 4x=7

Or x=

4

7

=1.75.

∴ The distance between the home & the school of the boy = 1.75 km.