Question

4. A passenger train takes 2 hours more than an express train to travel a distance of 240 km from Wardha to Akola. The speed of the passenger train is less than the express train by 20 km/hr. Find the average speed of both the trains.

Answer 1

Step-by-step explanation:

Velocity of passenger train=V

p

Velocity of express train=V

e

Time taken by passenger train =t

p

Time taken by express train =t

e

Distance traveled, s=V

p

t

p

=V

e

t

e

=240km

240=V

p

t

p

=(V

p

+20)(t

p

−2)

240=V

p

t

p

=V

p

t

p

−2V

p

+20t

p

−40

240=−2V

p

+20(

V

p

240

)−40

240V

p

=−2V

p

2

+4800−40V

p

−2V

p

2

−280V

p

+4800=0

2V

p

2

+280V

p

−4800=0

V

p

2

+140V

p

−2400=0

V

p

=

2

−140±

140

2

+4×2400

V

p

=15.44km/h (speed cannot be negative)

V

e

=V

p

+20=35.44km/h