A train moves past a telegraph post and a bridge 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train?

Answer: Option D

Explanation:

Let the length of the train be x metres and its speed by y m/sec.

Then,	x	= 8 x = 8y
	y

Now,	x + 264	= y
	20

8y + 264 = 20y

y = 22.

Speed = 22 m/sec =		22 x	18		km/hr = 79.2 km/hr.
			5