Aptitude - Clock

Exercise : Clock - General 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?
144°
150°
168°
180°
Answer: Option
Explanation:

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


2.
The reflex angle between the hands of a clock at 10.25 is:
180°
192 1 °
2
195°
197 1 °
2
Answer: Option
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 .
2 2 2


3.
A clock is started at noon. By 10 minutes past 5, the hour hand has turned through:
145°
150°
155°
160°
Answer: Option
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


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:
59 7 min. past 3
12
4 p.m.
58 7 min. past 3
11
2 3 min. past 4
11
Answer: Option
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.


5.
How much does a watch lose per day, if its hands coincide every 64 minutes?
32 8 min.
11
36 5 min.
11
90 min.
96 min.
Answer: Option
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