clock aptitude questions

1.

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.     144º    B.     150º
C.     168º    D.     180º
Answer & Explanation

Answer: Option D

Explanation:

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

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2.

The reflex angle between the hands of a clock at 10.25 is:
A.     180º    B.
192     1     º
2
C.     195º    D.
197     1     º
2
Answer & Explanation

Answer: Option D

Explanation:

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

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

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

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3.

A clock is started at noon. By 10 minutes past 5, the hour hand has turned through:
A.     145º    B.     150º
C.     155º    D.     160º
Answer & Explanation

Answer: Option C

Explanation:

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

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

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4.

A watch which gains 5 seconds in 3 minutes was set right at 7 a.m. In the afternoon of the same day, when the watch indicated quarter past 4 o’clock, the true time is:
A.
59     7     min. past 3
12
B.     4 p.m.
C.
58     7     min. past 3
11
D.
2     3     min. past 4
11
Answer & Explanation

Answer: Option B

Explanation:

Time from 7 a.m. to 4.15 p.m. = 9 hrs 15 min. =     37     hrs.
4

3 min. 5 sec. of this clock = 3 min. of the correct clock.

37     hrs of this clock =     1     hrs of the correct clock.
720     20

37     hrs of this clock =         1     x     720     x     37         hrs of the correct clock.
4     20     37     4

= 9 hrs of the correct clock.

The correct time is 9 hrs after 7 a.m. i.e., 4 p.m.

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5.

How much does a watch lose per day, if its hands coincide every 64 minutes?
A.
32     8     min.
11
B.
36     5     min.
11
C.     90 min.    D.     96 min.
Answer & Explanation

Answer: Option A

Explanation:

55 min. spaces are covered in 60 min.

60 min. spaces are covered in         60     x 60     min.     = 65     5     min.
55     11

Loss in 64 min. =         65     5     – 64         =     16     min.
11     11

Loss in 24 hrs =         16     x     1     x 24 x 60     min.     =     32     8     min.
11     64     11