Question

A train crosses a pole in $3$ seconds, and a $200$ metre long platform in 8 seconds, calculate the length of the train.

Answer 1

Let the length of the train be x metres.
Then Speed $=\frac{x}{3}=\frac{x+200}{8}[Speed=\frac{Distance}{Time}]$
$\frac{x}{3}=\frac{x+200}{8}$
$8x=3x+600$
$5x=600$
$\therefore x=120metres.$