Question

There are two trains. The first train crosses a pole in 24 sec, The second train of same length as that of the first train crosses a platform in 30 sec but the speed of the second train is 20% more than the first train. Find out the ratio of length of train and length of platform.

Answer 1

Answer:

2:1

Step-by-step explanation:

Let us assume that

length of the train= x meters and length of the platform = y meters.

If the speed of the first train is v meters/sec then the speed of the second train is (1+20/100)v=1.2v meters/sec.

Now, the first train crosses a pole in 24 sec. So, it covers x meter distance in 24 sec.

Hence, $\frac{x}{v}=24$ ...... (1)

Again, the second train crosses the platform in 30 sec. So, it covers (x+y) meters in 30 sec.

Hence, $\frac{x+y}{1.2v}=30$ ........ (2)

Now dividing (2) with (1), we get,

$\frac{x+y}{1.2x}=\frac{30}{24}$

⇒$\frac{x+y}{x}=\frac{30}{24} *1.2$

⇒$\frac{x+y}{x}=\frac{3}{2}$

⇒$\frac{y}{x} =\frac{1}{2}$

⇒$\frac{x}{y} =2$

Therefore the ratio of the lengths of the train and the platform is 2:1 (Answer)