Introduction to Elapsed Time

Elapsed time in simple terms is the amount of time that passes from the start of an event to its end. In this lesson, you will learn how to solve for elapsed time and explore how it can be used in your everyday life.

Say it is 3:15pm in the afternoon and you are to meet your friend at 6:25 pm. Before you leave you should shower, get dressed, and have time to get to your friend's house. Now you must figure out in how much time you must finish your tasks and arrive at 6:25pm.

Definition

Elapsed time is the amount of time that passes from the start of an event to its finish. In simple terms, elapsed time is the time that goes by from one time (say 3:15pm) to another (6:25pm).

The first thing you always do when solving for elapsed time is to find out your start time and end time. Here, start time is 3:15 pm and end time is 6:25 pm. Looking at a clock, we know that the next hour to pass after start time 3:15 pm would be 4:00pm. So, counting from 3:15 to 4:00 there are 45 minutes between the two times. Similarly, counting from 6:00pm to 6:25pm, we see that there are 25 minutes between the two times. We have now to count the hours in the middle. We see that there are two hours between 4:00pm and 6:00pm. The final step in finding out our elapsed time is to add together these durations.

So, elapsed time

= 45 min + 2 hours + 25 min

= 70 min + 2 hours

= 1 hour + 2 hour + 10 min

= 3 hours 10 minutes

How much time has elapsed during the following interval?

4:40 am to 7:20 am

Solution

Step 1:

Start time = 4:40 am; Final time = 7:20 am

Step 2:

To find the elapsed time, we subtract the start time from final time as follows

7:20 am – 4:40 am = 2:48 = 2 hours 40 minutes

How much time has elapsed during the following interval?

2:00 pm to 4:16 pm

Solution

Step 1:

Start time = 2:00 pm; Final time = 4:16 pm

Step 2:

To find the elapsed time, we subtract the start time from final time as follows

4:16 pm – 2:00 pm = 2:16 = 2 hours 16 minutes

How much time has elapsed during the following interval?

6:10 pm to 9:21 pm

Solution

Step 1:

Start time = 6:10 pm; Final time = 9:21 pm

Step 2:

To find the elapsed time, we subtract the start time from final time as follows

9:21 pm – 6:10 pm = 3:11 = 3 hours 11 minutes