Question

An express train travels at an average speed of 120 km per hour, stopping for 4 minutes after every 80 kms. How long will it take the train to reach a destination 960 km away?
$
  {\text{A}}{\text{. }}8hrs40\min \\
  {\text{B}}{\text{. }}8hrs44\min \\
  {\text{C}}{\text{. }}8hrs48\min \\
  {\text{D}}{\text{. }}8hrs56\min \\
 $

Answer 1

Hint: - Here we have to go through the concept of speed, time and distance we have to calculate the time by the help of distance and speed, and then add the time of stoppage of trains at the station.

Complete step-by-step answer:
Here in the question it is given that an express train travels at an average speed of 120 km per hour, stopping for 4 minutes after every 80 kms.
Speed of train =120 km/hr.
Distance=960 km
First we calculate the time taken by the train to cover the distance of 960km. as we know that the formula of calculating time is, time$ = \dfrac{{{\text{distance}}}}{{{\text{speed}}}}$.
By applying this formula we can write it as,
Time$ = \dfrac{{960km}}{{120km/hr}} = 8hr$.
And in the question it is also given that it stops at every 80 km.
So the total number of stoppage that the train stops is $\dfrac{{960}}{{80}} = 12$
But the first stoppage is not included because the trains start from that stoppage.
And at each stoppage the trains stop for 4min.
So for 11 stoppages time taken$ = 11 \times 4 = 44\min $
Therefore the total time taken is 8hrs + 44min=8hrs 44min
Hence option B is the correct answer.

Note: - Whenever we face such type of question the key concept for solving the question is to calculate the time taken by dividing the total distance by the speed and always keep in mind the unit of distance and speed we generally do mistakes here in such type of question so first make the units same for further calculation here in this question units are already same so we don’t need to change it.