Chapter 10 - Measuring Time
Problem Set 43
1. Write the time shown in each clock in the box given below it.
(i)
Ans: 25 minutes past 2
(ii)
Ans: 50 minutes past 7
(iii)
Ans: 5 minutes past 8
(iv)
Ans: 40 minutes past 4
2. Draw the hands of the clock to show the time given in the box.
(i) Four thirty
Ans:
(ii) Quarter past nine
Ans:
(iii) Quarter to five
Ans:
(iv) 20 minutes past 11
Ans:
3. If a bus that leaves Nashik at 5 o’clock in the morning reaches Pune that same day at ten thirty in the morning, how long does the journey take ?
Solution:
Bus leaves Nashik at time = 05:00 am
Bus reaches Pune at time = 10:30 am
Time taken to complete the journey = ?
Ans: The journey takes 15 hours and 30 minutes.
4. A play that was to start at nine fifteen at night was delayed by half an hour because of a power outage. What time did the play start?
Solution:
Play was to start at time = 09:15 pm
Time delay = 00:30 hours
Play started at time = ?
Ans: The play started at 09:45 pm.
5. If a train leaves Mumbai at ten fifteen at night and reaches Nagpur at one forty the next afternoon, how long does the journey take?
Solution:
Train leaves Mumbai at time = 10:15 pm
Train reaches Nagpur at time = 01:40 pm
The journey takes place over 2 dates (10:30 to midnight and midnight to afternoon)
So,
Date 1: Time take from 10:30 pm to midnight
Date 2: Time taken from midnight to 01:40 pm
According to the 24 hour format,
Midnight time = 00:00 hours
01:40 pm time = 13:40 hours
Total time taken =
Ans: Total time of the journey is 15 hours and 25 min
Problem Set 44
1. The time below is given by the 12 hour clock. Write the same by the 24 hour clock.
(i) 30 minutes past 10 in the morning
Ans: 10:30
(ii) 10 minutes past 8 in the morning
Ans: 08:10
(iii) 20 minutes past 1 in the afternoon
Ans: 13:20
(iv) 40 minutes past 5 in the evening
Ans: 17:40
2. Match the following.
| 12 hour clock | 24 hour clock |
|---|---|
9:10 am | 23:10 |
2:10 pm | 7:25 |
5:25 pm | 14:10 |
11:10 pm | 9:10 |
7:25 am | 17:25 |
Ans:
| 12 hour clock | 24 hour clock |
|---|---|
9:10 am | 9:10 |
2:10 pm | 14:10 |
5:25 pm | 17:25 |
11:10 pm | 23:10 |
7:25 am | 7:25 |
Problem Set 45
1. Add the following :
(1) 2 hours 30 minutes + 4 hours 55 minutes
Solution:
Ans: 2 hours 30 minutes + 4 hours 55 minutes = 07 hours and 25 minutes.
(2) 3 hours 50 minutes + 4 hours 20 minutes
Solution:
Ans: 3 hours 50 minutes + 4 hours 20 minutes = 08 hours and 10 minutes.
(3) 3 hours 45 minutes + 1 hour 35 minutes
Solution:
Ans: 3 hours 45 minutes + 1 hour 35 minutes = 05 hours and 20 minutes.
(4) 4 hours 15 minutes + 2 hours 50 minutes
Solution:
Ans: 4 hours 15 minutes + 2 hours 50 minutes = 07 hours and 05 minutes.
2. Subtract the following :
(1) 3 hours 10 minutes – 2 hours 40 minutes
Solution:
Ans: 3 hours 10 minutes – 2 hours 40 minutes = 00 hours and 30 minutes.
(2) 5 hours 20 minutes – 2 hours 35 minutes
Solution:
Ans: 5 hours 20 minutes – 2 hours 35 minutes = 02 hours and 35 minutes.
(3) 4 hours 25 minutes – 1 hour 55 minutes
Solution:
Ans: 4 hours 25 minutes – 1 hour 55 minutes = 02 hours and 30 minutes.
(4) 6 hours 15 minutes – 2 hours 45 minutes
Solution:
Ans: 6 hours 15 minutes – 2 hours 45 minutes = 01 hour and 30 minutes.
3. A government office opens at 7 in the morning and closes at 3 in the afternoon. How long is this office open?
Solution:
Opening time for office = 07:00 am
Closing time for office = 03:00 pm
According to 24 hour clock,
07:00 am = 07:00
03:00 pm = 15:00
The total time for which the office is open is,
Ans: The office is open for 08 hours.
4. A movie starts at 45 minutes past 3 in the afternoon and finishes two and a half hours later. At what time does the movie end?
Solution:
Movie starts at time = 03:45 pm
Duration of the movie = 02:30 hours
Movie ends at time,
Ans: The movie ends at 06:15 pm.
5. Sakharam was ploughing the field from 8 in the morning. At 12:30 in the afternoon he stopped and started for home. He reached home at 1:30. How long was he ploughing the field? How long did it take him to reach home from the field?
Solution:
Sakharam started ploughing at time = 08:00 am
He stopped ploughing at time = 12:30 pm
He reached home at time = 01:30 pm
According to 24 hour clock,
08:00 am = 08:00
12:30 pm = 12:30
01:30 pm = 13:30
The total time for which he was ploughing the field is,
The total time taken by him to reach home is,
Ans: The total time for which Sakharam was ploughing the field is 04 hours and 30 minutes and the total time taken by him to reach home is 01 hour.
6. Rambhau started the water pump at ten thirty at night and put it off the same night at a quarter to twelve. How long was the water pump on?
Solution:
Rambau started the water pump at time = 10:30 pm
He stopped the water pump at time = 11:45 pm
The total time for which the water pump was on is,
Ans: The water pump was on for 01 hour and 15 minutes.
7. Geeta taught in the classroom for 2 hours and 25 minutes in the morning and 1 hour and 45 minutes in the afternoon. How long was she teaching in all?
Solution:
Duration for which Geeta taught in the classroom in the morning = 02:25 hours
Duration for which Geeta taught in the classroom in the afternoon = 01:45 hours
The total time for which she was teaching in all is,
Ans: Geeta taught for 04 hours 10 minutes in all.
8. If a bank is open for business from 10 in the morning to 4:30 in the evening, how long is it open?
Solution:
Opening time for bank = 10:00 am
Closing time for office = 04:30 pm
According to 24 hour clock,
10:00 am = 10:00
04:30 pm = 16:30
The total time for which the bank is open is,
Ans: The bank is open for 06 hours and 30 minutes.
9. If a shop is open from 9:30 am to 10 pm, how long is it open?
Solution:
Opening time for shop = 09:30 am
Closing time for shop = 10:00 pm
According to 24 hour clock,
09:30 am = 09:30
10:00 pm = 22:00
The total time for which the shop is open is,
Ans: The shop is open for 12 hours and 30 minutes.
10. If the Maharashtra Express leaving from Kolhapur at 15:30 arrives at Gondia the next day at 20:15, how long is the journey from Kolhapur to Gondia?
Solution:
Leaving time from Kolhapur = 15:30 pm
Arriving time at Gondia = 20:15 pm (The next day)
The journey takes place from 15:30 pm to 20:15 the next day.
∴ 15:30 pm to next day’s 15:30 pm is 24 hours.
So, 15:30 pm to 20:15 pm is,
The duration of journey from Kolhapur to Gondia is,
Ans: The duration of journey from Kolhapur to Gondia is 28 hours and 45 minutes.