Question

An Express train makes a run of 240 km at a certain speed. Another train whose speed is 12 km per hour less takes an hour long to cover the same distance. find the speed of Express train in kilometre per hour

Answer 1

24km/hr
......................................................

Answer 2

Let x=speed of express prepare,

x-12=speed of slower prepare,

travel time=distance/speed,

240/(x-12)- 240/x=1,

LCD: x(x-12),

240x-240x+2880=x^2-12x, x^2-12x-2880,

(x+48)(x-60)=0, x=-48(reject x>0) or x=60,

ans: Speed of the express train=60 km/hr.

An express prepare makes a keep running of 240 km at a specific speed.

Another prepare whose speed is 12 km/hr less takes a hour longer to cover a similar separation.