Page 134 - Start Up Mathematics_3

Example 2: How many minutes or seconds are there in 2 hours?

Solution: Minutes in 1 hour = 60

Minutes in 2 hours = 60 × 2 = 120

Seconds in 1 minute = 60

Seconds in 120 minutes = 60 × 120 = 7200
Thus, there are 120 minutes or 7200 seconds in 2 hours.

EXERCISE 9.2

1. Anjali’s daily routine is given below. Write the duration of time for each activity.
(a) Wakes up in the morning: 6 o’clock

Goes to school: 7 o’clock Duration of time = _________

(b) Reaches school: 8 o’clock

Eats lunch: 11 o’clock Duration of time = _________

(c) Reaches home: 2 o’clock
Does homework: 4 o’clock Duration of time = _________

2. Write the time.

(a) (b)
Time now Time after 1 hour Time now Time 1 hour before

5 o’clock 7:00

8 o’clock 3:00

10 o’clock 9:00

11 o’clock

(c) (d)
Time now Time after 3 hours Time now Time 2 hours before

1:00 3:00

4:30 6:30

7:00 9:15

11:00

3. How many hours will be there in (a) 2 days, (b) 5 days and (c) 1 week?

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