Clock

Question:
How many times in a day, the hands of a clock are straight?

[A].

22

[B].

24

[C].

44

[D].

48

Answer: Option C

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.

Question: How many times do the hands of a clock coincide in a day?

[A].

20

[B].

21

[C].

22

[D].

24

Answer: Option C

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.

Question: The reflex angle between the hands of a clock at 10.25 is:
[A].

180°

[B].

192	1	°
	2

[C].

195°

[D].

197	1	°
	2

Answer: Option D

Explanation:

Angle traced by hour hand in	125	hrs =		360	x	125		°	= 312	1	°	.
	12			12		12				2

Angle traced by minute hand in 25 min =		360	x 25		°	= 150°.
		60

Reflex angle = 360° –		312	1	– 150		°	= 360° – 162	1	°	= 197	1°	.
			2					2			2

Question: At what angle the hands of a clock are inclined at 15 minutes past 5?
[A].

58	1	°
	2

[B].

64°

[C].

67	1	°
	2

[D].

72	1	°
	2

Answer: Option C

Explanation:

Angle traced by hour hand in	21	hrs =		360	x	21		°	=	157	1	°
	4			12		4					2

Angle traced by min. hand in 15 min. =		360	x 15		°	= 90°.
		60

Required angle =		157	1		°	– 90° = 67	1	°
			2				2

Question: The angle between the minute hand and the hour hand of a clock when the time is 4.20, is:
[A].

0°

[B].

10°

[C].

5°

[D].

20°

Answer: Option B

Explanation:

Angle traced by hour hand in	13	hrs =		360	x	13		°	= 130°.
	3			12		3

Angle traced by min. hand in 20 min. =		360	x 20		°	= 120°.
		60

Required angle = (130 – 120)° = 10°.

Question: The angle between the minute hand and the hour hand of a clock when the time is 8.30, is:
[A].

80°

[B].

75°

[C].

60°

[D].

105°

Answer: Option B

Explanation:

Angle traced by hour hand in	17	hrs =		360	x	17		°	= 255°.
	2			12		2

Angle traced by min. hand in 30 min. =		360	x 30		°	= 180°.
		60

Required angle = (255 – 180)° = 75°.

Question: At 3:40, the hour hand and the minute hand of a clock form an angle of:
[A].

120°

[B].

125°

[C].

130°

[D].

135°

Answer: Option C

Explanation:

Angle traced by hour hand in 12 hrs. = 360°.

Angle traced by it in	11	hrs =		360	x	11		°	= 110°.
	3			12		3

Angle traced by minute hand in 60 min. = 360°.

Angle traced by it in 40 min. =		360	x 40		°	= 240°.
		60

Required angle (240 – 110)° = 130°.

Question: An accurate clock shows 8 o’clock in the morning. Through how may degrees will the hour hand rotate when the clock shows 2 o’clock in the afternoon?
[A].

144°

[B].

150°

[C].

168°

[D].

180°

Answer: Option D

Explanation:

Angle traced by the hour hand in 6 hours =		360	x 6		°	= 180°.
		12

Question: A clock is started at noon. By 10 minutes past 5, the hour hand has turned through:
[A].

145°

[B].

150°

[C].

155°

[D].

160°

Answer: Option C

Explanation:

Angle traced by hour hand in 12 hrs = 360°.

Angle traced by hour hand in 5 hrs 10 min. i.e.,	31	hrs =		360	x	31		°	= 155°.
	6			12		6