Question

Delhi to Agra at an intervalo
ch with a speed of 30 km/h.
Two trains left Delhi to Agra at a
10 minutes and each with a speed
What was the speed of a third train moving to
Delhi, if it met these two trains at an interval of
- 4 minutes?
(1) 30 km/h
- (2) 45 km/h
(3) 15 km/h
(4) 20 km/h
​

Answer 1

the speed of the train coming from Delhi is also 2km /4minutes

now, the second to train coming from Delhi and the train from Agra covered a distance of 5km within 4minutes

va+vc=5km/4minutes

2km/4minutes+vc=5km/4minutes

vc=5-2=3km/4minutes

to make it to per hour just multiply it by 15(because 4minutes *15=60minute=1hours)

so the speed is 3*15=45km/hour