Question

If a train runs at 40kmph it reaches its destination late by 11 minutes but if it runs at 50 kmph it late by 5 minutes only find the distance to be covered by train

Answer 1

Let the distance to be covered by train = S km
Let the time taken by train if it arive at the right time = t hours.

{
11 min = 11/ 60 hour
5 min = 5/60 hour.
}
A/Q,
Speed of train A = 40 KM/Hour.
Time taken by train A = t+11/60  hours.

S = 40*(t+11/60) 
S = 40t + 22/3   ---------------(1)
and,
Speed of train B = 50 KM/Hour.
Time taken by train B = t+5/60  hours.
S= 50( t +5/60)
S = 50t + 25/6 -----------------(2)
By suntracting 50×eqn(1) - 40×eqn(2)
50*S - 40*S = 2000t + 1100/3 - 2000t - 500/3
10*S = 600/3
10*S = 200
S = 20 KM
Therefore total distance to be covered is 20 KM.