Explanation: The 24-hour clock, also known as military time, is a time convention where the day runs from midnight to midnight and is divided into 24 hours, numbered from 00 to 23. This system is widely used in India and many other countries for official and professional purposes, including railway timetables, flight schedules, and military operations.
To calculate the duration of a journey using the 24-hour clock, you need to subtract the departure time from the arrival time. In this case, the Karnataka Express leaves Itarsi at 0840 hours and reaches Bhusaval at 1310 hours on the same day. The departure time is 0840 hours, and the arrival time is 1310 hours.
The calculation is straightforward:
1. Subtract the departure time from the arrival time:
\[
1310 - 0840 = 0430
\]
2. The result, 0430, represents 4 hours and 30 minutes.
Therefore, the journey takes 4 hours and 30 minutes.
It is important to note that when performing time subtraction, you should handle the hours and minutes separately. If the minutes of the departure time are greater than the minutes of the arrival time, you need to borrow an hour from the hours part of the arrival time and add 60 minutes to the minutes part of the arrival time before performing the subtraction.
In this problem, the minutes part of the departure time (40) is less than the minutes part of the arrival time (10), so no borrowing is necessary. The calculation is straightforward, and the result is 4 hours and 30 minutes.
Understanding the 24-hour clock and how to perform time calculations is crucial for various competitive examinations and real-life applications, such as managing schedules and understanding timetables.