Question

How much time has elapsed between $ 3 $ hours $ 12 $ minutes $ 35 $ seconds and $ 7 $ hours $ 54 $ minutes $ 34 $ seconds?

Answer 1

Hint: Elapsed time can be defined as how long something has taken place. To calculate the elapsed time first of all count in minutes from the earlier time to the nearest hour, then count on in hours to the hour nearest to the later time and then at last count in minutes to reach the later time.

Complete step by step solution:
First of all we will note down the relation between hours, minutes and seconds.
 $ 1 $ hour $ = 60 $ minutes
 $ 1 $ minute $ = 60 $ seconds
Now, observe the elapsed time give –
 $ 3 $ hours $ 12 $ minutes $ 35 $ seconds and
 $ 7 $ hours $ 54 $ minutes $ 34 $ seconds
We have to subtract the start time from finish time. Here we observe that start seconds is greater than the finish seconds. Therefore, subtract one minute from the finish time and add sixty seconds in finish time.
 $ 7 $ hours $ 54 $ minutes $ 34 $ seconds \[ = 7\] hours $ 53 $ minutes $ 94 $ seconds
Now, subtract start time from finish time
 $ 7 $ hours $ 53 $ minutes $ 94 $ seconds
 $ - \;3 $ hours $ 12 $ minutes $ 35 $ seconds
 $ 4 $ hours $ 41 $ minutes $ 59 $ seconds
This is the required solution.
So, the correct answer is “ $ 4 $ hours $ 41 $ minutes $ 59 $ seconds”.

Note: In simple terms, elapsed time can be defined as the difference between two times. Elapsed time is also known as the time interval. It is the amount of time which passes from the start of an event to its finish. An important tool which goes hand in hand with the elapsed time is the clock.