HOW TO ADD AND SUBTRACT TIME IN HOURS AND MINUTES

Problem 1 :

What is the time 3 hours 40 minutes before 9: 15 am?

Solution:

The time is 9:15 - 3 hours 40 minutes

= 9 hours + 15 min - 3 hours - 40 min

= 6 hours + 15 min - 40 min

= 5 hours + 60 min + 15 min - 40 min

= 5 hours + 35 mins

So, the time is 5:35 am.

Problem 2 :

Find the following:

3 h 7 min + 5 h 23 min

Solution:

= 3 h 7 min + 5 h 23 min

= 3 hours + 7 min + 5 hours + 23 min

= 8 hours + 30 min

= 8 hours 30 min

Problem 3 :

5 h 17 min + 3 h 25 min + 4 h 35 min

Solution:

= 5 h 17 min + 3 h 25 min + 4 h 35 min

= 5 hours + 17 min + 3 hours + 25 min + 4 h + 35 min

= 12 hours + 77 min

= 12 hours + 60 min + 17 min

= 12 hours + 1 hour + 17 min

= 13 hours 17 min

Problem 3 :

7 h 53 min - 3 h 36 min

Solution:

= 7 h 53 min - 3 h 36 min

= 7 hours + 53 min - 3 hours - 36 min

= 4 hours + 17 min

= 4 hours 17 min

Problem 4 :

11 h 43 min + 2 h 24 min + 5 h 16 min

Solution:

= 11 h 43 min + 2 h 24 min + 5 h 16 min

= 11 h + 43 min + 2 h + 24 min + 5 h + 16 min

= 18 h + 83 min

= 18 h + 60 min + 23 min

= 18 h + 1 h + 23 min

= 19 h 23 min

Problem 5 :

17 h 42 min - 12 h 53 min

Solution:

= 17 h 42 min - 12 h 53 min

= 4 h 49 min

Problem 8 :

10 h 32 min + 5 h 47 min - 7 h 57 min

Solution:

10 h 32 min + 5 h 47 min :

16 h   19 min - 7 h   57 min :

8 hour and 22 minutes.