Question

The length of a train is half that of the length of a platform. If it is travelling with a speed of 54 km/hr and
crosses the platform in 21/3 minutes, then what is the length of the train?
A. 1400m
B. 700m
C. 2100m
D. 1000m​

Answer 1

Answer:  Hence the length of train is 2100 meters.

Step-by-step explanation:

Alright, lets get started.

Suppose the length of the train is x.

The length of a train is half that of the length of a platform.

So, length of the platform will be : $2x$

If it is traveling with a speed of 54 km per hr and crosses the platform in  $\frac{21}{3}$minutes.

Means , the distance traveled in $\frac{21}{3}$ minutes will be 2x and x. (length of platform and length of train itself)

Speed of train is 54 km per hr, converting it into meter per second, it will be : $54*\frac{5}{18} =15 \ meter \ per \ second$

Converting $21/3$ minutes into seconds : $\frac{21}{3}*60 = 420 \ seconds$

$distance = time*speed$

$3x = 420*15$

$x=2100$

Hence the length of train is 2100 meters.   :   Answer

Hope it will help :)

Answer 2

Answer:

answer is here please like the answer and follow