Question

Find the angle between the min hand and hour hand when the time is 7:20

Answer 1

Answer:

Let us quickly recall few basic facts about clocks:

Complete rotation of a needle makes 360 degrees in a clock.

There are total 12 big divisions making each division of (360/12 ) = 30 degree.

At 7:20 AM/PM, big needle is at 4 while the small needle slightly shifts away from 7. So, let us find out the rotational angle of small needle (which is due to rotation of big needle from 12 to 4).

When the big needle rotates 360 degree (60 minutes), the small needle rotates 1 hour which means 360/12 = 30 degree.

Hence, when the big needle rotates 120 degree, the small needle rotates by 30/3 = 10 degree

Hence, at 7:20 AM/PM:

The minute needle is at an angle of 120 degree clockwise.

The hour needle is at 210+10 = 220 degree clockwise.

So, the minimum angle = 220 - 120 = 100 degree.

Step-by-step explanation: