AFCAT Model Paper 8

Given:
The average speed of train = 40 km/hr
If the average speed is 35 km/hr then it is delayed by 15 minutes.
Formula Used:
Time = Distance/Speed
Calculation:
Let the distance of total journey be ‘d’ km.
Case 1st :
Given, with an average speed of 40 km/hr, a train reaches its destination in time.
Speed = 40 km/hr, Time = d/40 hr
This is the time actually required for the journey.
Case 2nd :
Given, with an average speed of 35 km/hr, it is late by 15 minutes.
Speed = 35 km/hr, Time =

d

35

As he is late by 15 minutes, the actual time for journey =(

d

35

−

15

60

)hr
Actual time of journey should be same.
⇒

d

40

=

d

35

–

1

4

⇒

1

4

=

d

35

–

d

40

⇒

1

4

=

d

280

⇒ d = 70 km
∴ The required distance is 70 km.