Question

the speed of express train is 10km/hr slower than the speed of superfast train . if the suferfast train takes 30 minutes to cover a distance of 80 km. find the time taken by express train to cover the distance

Answer 1

Answer:

let the speed of superfast train be x

speed of express train =x-10

time =1/2 hour

distance=80 km

speed =d/t

=80/30

8/3=x-10

x=8/3+10/1

x=8/3+30/3

x=38/3 km/h

speed of superfast train =38/3 km/h

speed of express train =38/3-10/1

=8/3 km/h

distance=80 km

time=d/s

80/8*3

=30 hours

Answer 2

Answer:

32 minutes

Step-by-step explanation:

1st step:calculate the speed of superfast train

distance=80 km

time taken=30 minutes=(30/60)hr=1/2hr

Using,speed=distance/ time

Speed of superfast train=80*(1/2)km/hr=(80*2)km/hr=160km/hr

2nd step:

it is given that speed of express is 10km/hr slower than superfast train

ATQ,

speed of express train=(160-10)km/hr=150km/hr

distance=80 km

speed=150km/hr

using ,time=distance/speed

time taken=(80/150)hr=(80/150)*60 minutes

therefore time taken by express train=32 minutes