A train crosses a pole in 8 seconds. The length of the train is 120 meters. Find the time taken (in seconds) by the train to cross a platform of length 120 meters.

The correct answer is 16.

Step 1: Find the speed of the train.
When a train crosses a stationary pole, the distance covered is equal to the length of the train itself.
Given:
Length of the train = 120 meters
Time taken to cross the pole = 8 seconds

Using the formula for speed:
$\text{Speed}=\frac{\text{Distance}}{\text{Time}}$

Substituting the given values:
$\text{Speed of the train}=\frac{120\text{meters}}{8\text{seconds}}=15\text{m/s}$

Step 2: Find the time taken to cross the platform.
When the train crosses a platform, the total distance covered is the sum of the length of the train and the length of the platform.
Given:
Length of the platform = 120 meters

$\text{Total Distance}=\text{Length of train}+\text{Length of platform}$

$\text{Total Distance}=120\text{m}+120\text{m}=240\text{meters}$

Using the formula for time:
$\text{Time}=\frac{\text{Total Distance}}{\text{Speed}}$

Substituting the values:
$\text{Time taken}=\frac{240\text{meters}}{15\text{m/s}}=16\text{seconds}$

Therefore, the train takes 16 seconds to cross the platform.