Clock

A clock has 2 hands, the smaller one is called the hour hand or short hand while the larger one is called the minute hand or long hand.

The face of a clock is a circle which subtends an angle of 360° at the centre.

Some Important Points

In every hour
1. (a) Both the I ands coincide once. At this point the angle between them is 0°..
(b) The hands are straight (point in opposite directions) once. At this point the angles between them are 180°.
(c) The hands are twice perpendicular to each other. At this point the angle between them is 90°.

2. (a) In 60 min the minute hand covers 360°.

3. (a) When the two hands are at right angles, they are 15min spaces apart.
(b) When the two hands are in opposite directions, they are 30 min spaces apart.
(c) In 60 min the minute hand gains 55 min on the hour hand.
(d) The minute hand moves 12 times as fast as the hour hand.

4. (a) Too Fast: If a clock indicates 7 : 1.5, when the correct time is 7, it is said to be 15 min too fast.
(b) Too Slow: If a clock indicates 7 : 30, when the correct time is 7 45 , it is said to be 15 min too slow.

Calendar

1. Odd Days:

2. Ordinary Year:

3. Leap Year:

4. Counting of Odd Days

5. Day of the week with respect to the number of odd days.
Number of odd days Day of the week
0              Sunday
1             Monday
2             Tuesday
3             Wednesday
4             Thursday
5             Friday
6             Saturday