At 60% of its usual speed, a train of length L metres crosses platform

1.	At 60% of its usual speed, a train of length L metres crosses platform 240 metreslong in 15 seconds. At its usual speed, the train crosses a pole in 6 seconds. Whatis the value of L (in metres)?
Answer» Answer: Answer: Option D. Let usual speed = S m/s. According to the question, 60% of S= (L+240)/15 9S= L+240………… (i) ALSO GIVEN that, S = L/6 L = 6S …. (II) From (i) & (ii) 9S= 6S+240 3S= 240 S=80 m/s From (ii) L= 6×80 =480

At 60% of its usual speed, a train of length L metres crosses platform 240 metreslong in 15 seconds. At its usual speed, the train crosses a pole in 6 seconds. Whatis the value of L (in metres)?

Answer»

Answer:

Answer: Option D.

Let usual speed = S m/s.

According to the question,

60% of S= (L+240)/15

9S= L+240………… (i)

ALSO GIVEN that, S = L/6

L = 6S …. (II)

From (i) & (ii)

9S= 6S+240

3S= 240

S=80 m/s

From (ii)

L= 6×80 =480