Aptitude - Clock

Exercise :: Clock - General Questions

6. 

At what time between 7 and 8 o'clock will the hands of a clock be in the same straight line but, not together?

A. 5 min. past 7
B.
5 2 min. past 7
11
C.
5 3 min. past 7
11
D.
5 5 min. past 7
11

Answer: Option D

Explanation:

When the hands of the clock are in the same straight line but not together, they are 30 minute spaces apart.

At 7 o'clock, they are 25 min. spaces apart.

Minute hand will have to gain only 5 min. spaces.

55 min. spaces are gained in 60 min.

5 min. spaces are gained in 60 x 5 min = 5 5 min.
55 11

Required time = 5 5 min. past 7.
11


7. 

At what time between 5.30 and 6 will the hands of a clock be at right angles?

A.
43 5 min. past 5
11
B.
43 7 min. past 5
11
C. 40 min. past 5
D. 45 min. past 5

Answer: Option B

Explanation:

At 5 o'clock, the hands are 25 min. spaces apart.

To be at right angles and that too between 5.30 and 6, the minute hand has to gain (25 + 15) = 40 min. spaces.

55 min. spaces are gained in 60 min.

40 min. spaces are gained in 60 x 40 min = 43 7 min.
55 11

Required time = 43 7 min. past 5.
11


8. 

The angle between the minute hand and the hour hand of a clock when the time is 4.20, is:

A.
B. 10°
C.
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°.


9. 

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


10. 

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°.