If a train runs at 70 km/hour, it reaches its destination

If a train runs at 70 km/hour, it reaches its destination late by 12 minutes. But if it runs at 80 km/ hour, it is late by 3 minutes. The correct time to cover the journey is

Distance of journey = x km
Difference of time = 12 – 3 = 9 minutes

=	9	hour =	3	hour
	60		20

∴	x	−	x	=	3
	70		80		20

⇒	x	−	x	=	3
	7		8		2

⇒	8x − 7x	=	3
	56		2

⇒	x	=	3
	56		2

⇒ x =	3	× 56 = 84 km
	2

∴ Required correct time

=	84	hours – 12 minutes
	70

=		84	× 60 − 12		minutes
		70

= 72 – 12 = 60 minutes
= 1 hour