[Math] Hands of a clock forming certain angles

arithmeticrecreational-mathematics

How many times to the hands of a clock form a 60 degree angle between noon and midnight on the same day?

Firstly im not sure weather they require the second hand to be included.

And secondly (excuse the pun) i have no clue how to start the problem.

Thanks.

Best Answer

Hint

Total angle swept by the pins on a clock $ = 360^{\ \text{o}} $

Smallest unit on clock (for recreational questions, second hand is NOT taken into consideration) $ = 1 $ minute

$ \therefore $ Area swept per minute $ \implies 6^{\text{ o}} $.


Hence, to generate an angle of $ 60^{\text{ o}} $ (between hour and minute hands), they should be $ 10 $ units apart.