- Problems in angles
- Problems on incorrect clocks
- Speed of the hour hand = 0.5 degrees per minute (dpm)
- Speed of the minute hand = 6 dpm
- At ‘n’ o’ clock, the angle of the hour hand from the vertical is 30n
Angle between X and Y =|(X*30)-((Y*11)/2)|
- Two right angles per hour(Right angle = 90, Straight angle=180)
- Forty four right angles per day
- Between every two hours the hands of the clock coincide with each other for one time except between 11, 12 and 12, 1.In a day they coincide for 22 times.
- Between every two hours they are perpendicular to each other two times except between 2, 3 and 3, 4 and 8, 9 and 9, 10.In a day they will be perpendicular for 44 times.
- Between every two hours they will be opposite to each other one time except between 5, 6 and 6, 7.In a day they will be opposite for 22 times.