Question

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

Answer 1

answer :

L = 480 meter

explaination :

speed of train = 10x ms

lenght ,, ,, = L

time taken to cross the pole = 6 sec

speed = distance / time

10x = 1/6

x. = 1/6(10) = 1/60

case 2

speed is 60% = 60/100(10x) = 6x ms

lenghth crosses platform = 240 m

6 into L/60 = 240 + L / 15

L/ 10 = 240+ L / 15

15 L = 2400 + 10 L

15L - 10 L = 5 L = 2400

L = 2400/5

L = 480 meter