Discussion Forum



1)

A 300 metre long train crosses a platform in 39 seconds while it crosses a signal pole in 18 seconds. What is the length of the platform ?


A) 320 m

B) 350 m

C) 650 m

D) Data inadequate

E) None of these

Answer:

Option B

Explanation:

Speed $=\left(\frac{300}{18}\right)$ m/sec $=\frac{50}{3}$ m/sec.

Let the length of the platform be $x$ metres.

Then, $\frac{x+300}{39}$ $=\frac{50}{3}$

$\Leftrightarrow 3(x+300)$ $=1950$ $\Leftrightarrow x=350$ m.