The Time Trick
Geometry
Level
2
Find the angle in degrees between the minute and the hour hand of wall clock when it is showing 7:20 AM/PM.
The answer is 100.
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1 solution
Moderator note:
Simple standard approach.
The entire clock is divided into 12 equal parts of 30 degrees. For 20 minutes , angle covered is : 30 * 4 = 120 degrees. Now since the hour hand first goes to 7, so angle is 7 * 30 = 210 degrees. At the moment when the minute hand is at 12 and hour at 7, angle is 210. Now , for 60 minutes hour hand moves by 30 degree for 20 minute hour hand rotates by 6 0 3 0 *2 degrees. Theefore angles between hour and minute hand = (210+10-120) degrees = 100 degrees