Question

Find the angle between the minute hand and the hour hand of a clock when the time is 7:20 am.

Answer 1

in this problem simple trick for finding angle

30H - 11/2M = angle

where H = hours

M = minutes

30 × 7 - 11/2 × 20

= 210 - 110

= 100°

Answer 2

There are 360 deg in a circle so the angle between each hour is 360 / 12 = 30 deg. At 7:20 The minute hand points exactly at the 4 and the hour hand between the 7 & 8. 20 minutes is a third of an hour so the hour hand has travelled 30 / 3 = 10 deg beyond the 7.
So the angle is 30 * 3 + 10 = 100 deg.