Question

A train running at 18 km per hour crosses a mark on the platform in 9 seconds and takes 25 seconds to cross the platform. If P is the length of the train and Q is the length of the platform in meters, then (P, Q) =

A.
(45, 80)
B.
(45, 75)
C.
(50, 90)
D.
(50, 80)

Accepted Answer

A. Speed = $18 	imes \frac{5}{18} = 5$ m/s. Length of train $P = 5 	imes 9 = 45$ meters. Time to cross platform = $25$ seconds $\Rightarrow P + Q = 5 	imes 25 = 125$. $Q = 125 - 45 = 80$ meters. Thus, $(P, Q) = (45, 80)$.

Train Length and Platform Length

Explanation

Practise this under exam conditions