A goods train runs at the speed of 72 kmph and crosses a 250 m long platform in 26 seconds. What is the length of the goods train?

A. 290 m
B. 275 m
C. 270 m
D. 250 m

Solution:

$\left. \begin{array} { l } { \text { Speed } = ( 72 \times \frac { 5 } { 18 } ) m / sec = 20 m / sec } \\ { \text { Time } = 26 sec } \\ { \text { Let the length of the train be } x \text { metres. } } \\ { \text { Then, } \frac { x + 250 } { 26 } = 20 } \\ { \Rightarrow x + 250 = 520 } \\ { \Rightarrow x = 270 m } \end{array} \right.$