Types of Questions
1. Position of hands of the clock or angle between them2. Faulty clock
Concept and Formula:
⇒ Minute hand traces in 60 minutes = hour hand traces in 12 hours = 360⁰
⇒ Angle of Hour space = 30⁰ Angle of minute space = 6⁰
⇒ Angle between minute hand and hour hand
=
Example: angle between minute and hour hand at 10:27am
= 
⇒ Minute hand and hour hand overlap/coincide/0⁰ angle : when M
⇒ Minute hand and hour hand overlap/coincide/0⁰ angle : when M
=
In 12 hours = 11 times hands overlap
⇒ 180⁰angle between hands or in a straight line:
M =
[Add if hour hand is at from 1 to 5; subtract if from 6 to 12]
In 12 hours = 11 times hands are in straight line
⇒ Both hands are perpendicular/ at 90⁰angle :
[Add if hour hand is at from 1 to 5; subtract if from 6 to 12]
In 12 hours = 11 times hands are in straight line
⇒ Both hands are perpendicular/ at 90⁰angle :
M =
In 12 hours = 22 times hands are perpendicular to each other means in an hour, hands are perpendicular at two times so to find out exact time
Now, if value of (H ± 3) < 0 then adds 12 to find the exact value of minute
If value of (H ± 3) ≥ 12 then subtract 12 to find the exact value of minute
Example: To find the time between 9 to 10 o’clock when an hour and minute hands are perpendicular to each other.
Between 9 to 10 o’clock at 9 o’clock and 9:32 o’clock both hands with be at a right angle.
In 12 hours = 22 times hands are perpendicular to each other means in an hour, hands are perpendicular at two times so to find out exact time
Now, if value of (H ± 3) < 0 then adds 12 to find the exact value of minute
If value of (H ± 3) ≥ 12 then subtract 12 to find the exact value of minute
Example: To find the time between 9 to 10 o’clock when an hour and minute hands are perpendicular to each other.
Between 9 to 10 o’clock at 9 o’clock and 9:32 o’clock both hands with be at a right angle.
