A train crosses a platform in 20 seconds and a pillar situated on the platform in 8 seconds. If length of the platform is 264 meters, then length of the train is

Correct option is B

Given:

Time to cross platform = 20 seconds

Time to cross pillar = 8 seconds

Length of platform = 264 metres

Formula Used:

Speed = $$\frac{\text{Distance}}{\text{Time}}$$​​

Solution:

Let length of train = L metres

Crossing pillar:

Speed = $$\frac{L}{8}$$​​

Crossing platform:

Speed = $$\frac{L + 264}{20}$$​​

Since speed is same:

​$$\frac{L}{8} = \frac{L + 264}{20}$$​​

20L = 8(L + 264)

20L = 8L + 2112

12L = 2112

L = 176

Thus, Length of the train = 176 metres

Alternate Solution (Exam Trick):