Clocks and Time Quantitative Aptitude Test

  • 1. How many times do the hands of a clock coincide in a day? 
A.) 20
B.) 21
C.) 22
D.) 23

Answer: Option 'C'

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). 
==> The hands coincide 22 times in a day.

  • 2. How many times are the hands of a clock at right angles in a day? 
A.) 22
B.) 44
C.) 38
D.) 48

Answer: Option 'B'

In 12 hours, they are at right angles 22 times. 
=> In 24 hours, they are at right angles 44 times.

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

Answer: Option 'A'

55 min. spaces are covered in 60 min.
60 min spaces are covered in (60/55 × 60)min = 65 5/11 min
Loss in 64 min = ( 65 5/11- 64 ) = 16/11 min
Loss in 24 hrs = ( 16/11 × 1/64 × 24 × 60 ) min
= 32 8/11 min

  • 4. How many times in a day the hands of a clock are straight?
A.) 22
B.) 21
C.) 43
D.) 44

Answer: Option 'D'

In 12 hours, the hands coincide or are in oppesite direction 22 times. 
In 24 hours, they are at right angles 22 times.

  • 5. At what time between 4 & 5 will the hands of a watch point in opposite directions?
A.) 43 min past 4
B.) 42 5/11 min past 4
C.) 50 4/11 min past 4
D.) 40 min past 4

Answer: Option 'C'

At 4 o'clock, the hands of the watch are 20 min. spaces apart. 
To be in opposite directions, they must be 30min. spaces apart. 
Minute hand will have to gain 5 min. spaces. 
55min spaces are gained in 60 min. 
5 min. spaces are gained in (60/55 × 50) min. or 54 6/11 min.
Required time = 54 6/11 min. past 4.