A student goes to school at the rate of 21km/hr and reaches

A student goes to school at the
rate of 2
1 km/hr and reaches 6 minutes late.
2
If he travels at the speed of 3 km/hr. he is 10 minutes early. What is the distance to the school?

Let the distance of school be x km.
Difference of time = 6 + 10

= 16 minutes =	16	hour
	60

=	4	hour
	15

Time =	Distance
	Speed

∴	x	−	x	=	4
	5/2		3		15

⇒	2x	−	x	=	4
	5		3		15

⇒	6x − 5x	−	4
	15		15

⇒ x = 4 km.

Here, S₁ = 2,	1	t₁ = 6
	2

S₂ = 3, t₂ = 10

Distance =	(S₁ × S₂)(t₁ + t₂)
	S₂ − S₁

= 15 ×	16
	60

=	16	= 4 km
	4