Page 172 - ICSE Math 5

Conversion of Hours to Minutes and Vice Versa

We can convert hours to minutes and minutes to hours as follows:

1 hour (h) = 60 minutes (min) and 1 minute (min) = 1 hour (h)
60
• To convert hours and minutes to minutes, multiply the given hours with 60 and add the
given minutes to it.

• To convert minutes to hours and minutes, divide the given minutes by 60. Write the quotient
obtained as number of hours and remainder as number of minutes.

Example 3: Convert 12 hours 15 minutes to minutes.
Solution: 12 hours 15 minutes = (12 × 60) minutes + 15 minutes
= 720 minutes + 15 minutes = 735 minutes

Example 4: Convert 465 minutes to hours and minutes.

Solution: 465 minutes = 465 (since 1 minute = 1 hour)
60 60
= 7 hours 45 minutes

Conversion of Minutes to Seconds and Vice Versa

We can convert minutes to seconds and seconds to minutes as follows:

1
1 minute (min) = 60 seconds (s) and 1 second (s) = minute (min)
60
• To convert minutes and seconds to seconds, multiply the given minutes with 60 and add
the given seconds to it.

• To convert seconds to minutes and seconds, divide the given seconds by 60. Write the
quotient obtained as number of minutes and remainder as number of seconds.
Example 5: Convert 240 minutes to seconds.

Solution: 240 minutes = 240 × 60 seconds = 14,400 seconds
Example 6: Convert 3,600 seconds to minutes.

Solution: 3,600 seconds = 3,600 minutes = 60 minutes
60

Exercise 12.1

1. Convert the following to minutes.
(a) 5 hours (b) 12 hours (c) 7 hours 30 minutes

(d) 2 hours 10 minutes (e) 7 hours 5 minutes (f) 4 hours 55 minutes
2. Convert the following to hours and minutes.

(a) 145 minutes (b) 100 minutes (c) 350 minutes
(d) 540 minutes (e) 125 minutes (f) 450 minutes

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