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OverviewExercise"Hold a true friend with both hands."
- (Proverb)
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| 16. |
At what time, in minutes, between 3 o'clock and 4 o'clock, both the needles will coincide each other?
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Answer: Option D
Explanation:
At 3 o'clock, the minute hand is 15 min. spaces apart from the hour hand.
To be coincident, it must gain 15 min. spaces.
55 min. are gained in 60 min.
| 15 min. are gained in |
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60 |
x 15 |
 min |
= |
16 |
4 |
min. |
| 55 |
11 |
 The hands are coincident at 16 |
4 |
min. past 3. |
| 11 |
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| 17. |
How many times do the hands of a clock coincide in a day?
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Answer: Option A
Explanation:
The hands of a clock coincide 11 times in every 12 hours (Since between 11 and 1, they coincide only once, i.e., at 12 o'clock).
AM
12:00
1:05
2:11
3:16
4:22
5:27
6:33
7:38
8:44
9:49
10:55
PM
12:00
1:05
2:11
3:16
4:22
5:27
6:33
7:38
8:44
9:49
10:55
The hands overlap about every 65 minutes, not every 60 minutes.
The hands coincide 22 times in a day.
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| 18. |
How many times in a day, the hands of a clock are straight?
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Answer: Option B
Explanation:
In 12 hours, the hands coincide or are in opposite direction 22 times.
In 24 hours, the hands coincide or are in opposite direction 44 times a day.
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| 19. |
A watch which gains uniformly is 2 minutes low at noon on Monday and is 4 min. 48 sec fast at 2 p.m. on the following Monday. When was it correct?
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| A. |
2 p.m. on Tuesday | B. |
2 p.m. on Wednesday | | C. |
3 p.m. on Thursday | D. |
1 p.m. on Friday |
Answer: Option C
Explanation:
Time from 12 p.m. on Monday to 2 p.m. on the following Monday = 7 days 2 hours = 170 hours.
| The watch gains |
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2 + 4 |
4 |
min. |
or |
34 |
min. in 170 hrs. |
| 5 |
5 |
| Now, |
34 |
min. are gained in 170 hrs. |
| 5 |
| 2 min. are gained in |
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170 x |
5 |
x 2 |
hrs |
= 50 hrs. |
| 34 |
Watch is correct 2 days 2 hrs. after 12 p.m. on Monday i.e., it will be correct at 2 p.m. on Wednesday.
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