Description for Correct answer:
Let the length of the train be x m.

Now, speed = 48 km/h = \( \Large 48 \times \frac{5}{18} m/s \)

Train takes 9 s to cross a pole.

Therefore, Length of train, x = Speed X Time

= \( \Large 48 \times \frac{5}{18} \times 9 \) = 120m