Two trains, in which one train is 50 meters longer
than another, are running in opposite directions and
crosses each other in 10 seconds. If they run in the
same direction, the fast moving train crosses the
second train in 1 minute & 30 seconds. If the speed
of the fast moving train is 90 kmph, then what is the
length of each train?
Answers
Let the length of trains be x m and (x + 50)m and the speed of other train be y m per sec.
The speed of the first train = 90 km per hr.
= 90 ×
5
= 25 m per sec.
18
Case : I Opposite direction,
Their relative speed = (y + 25)m per sec.
Distance covered = x + x + 50 = 2x + 50 metres
∴ Time taken =
2x + 50
= 10
y + 25
⇒ 2x + 50 = 10y + 250 ...(i)
Case II. Direction is Same
Their relative speed = (25 – y) m per sec.
Distance covered = x + x + 50 = 2x + 50m
∴ Time taken =
2x + 50
= 90
25 − y
⇒ 2x + 50 = 90 (25 – y) ...(ii)
From equations (i) and (ii)
10y + 250 = 2250 – 90y
⇒ 10y + 90y = 2250 – 250
⇒ y =
2000
= 20
100
Putting y = 20 in equation (i), we have
2x + 50= 10 × 20 + 250 = 450
⇒ 2x = 450 – 50 = 400
⇒ x =
400
= 200
2
∴ x + 50 = 200 + 50 = 250 metres.
Hence,
The length of the 1st train = 200 metres.
The length of the 2nd train = 250 metres.
The speed of the 2nd train = 20 m per sec.
Answer:
Step-by-step explanation:
50 of course!