# What will be the Length of Platform? if

A 300-metre long train crosses a platform in 39 seconds while it crosses a single pole in 18 seconds. What is the length of the platform?

- 320m
- 350 m
- 650 m
- 680 m

**Answer: (2) 350 m**

**Explanation:-**

Let be the length of the platform = X m

The length of the train = 300 m

Total distance covered by train = (X + 300) m

Time take by train to cross the platform = 39 sec

**Formula-**

**Time = distance/speed**

Then, (X + 300)/speed = 39 …………………… (1)

Time taken by a train to cross the pole = 18 sec

Then, the speed of the train = 300/18 = 50/3 m/sec

The value of speed put in equation (1)

Then, (X + 300) x 3 /50 = 39

(X + 300) = 13 x 50

X + 300 = 650

X = 650 – 300

X = 350 m

Hence, the length of the platform is 350 m.