Question

The speed of train A is 10 km/h more than train B. If the train A takes 5 hours less than the train B to cover a distance of 300 km, find their spens.

Answer 1

let speed of train B is x km/h
and speed of train A is (10+x)km/h
also time taken by train B is t secs
time taken by train A is (t-5)secs
given s=300km
xt=300
or
t=300/x
(10+x)(t-5)=300
10t-50+xt-5x=300
10t-50+(300/t)*t-5*300/t=300
10t-1500/t=50
10t^2-1500=50t
10t^2-50t-1500=0
t^2-5t-150=0
t^2-15t+10t-150=0
t(t-15) +10(t-15)=0
(t+10)(t-15)=0
t=15 secs
time taken by following trains are:
A=10 secs
B=15 secs