August 2012
Problem of the Month

Clock Problem

From midnight one day to midnight the next, exactly how many times do the hands of a clock form a perfect 90 degree angle?

Solution to the Problem:

44 times.

Twice every hour, except for 2:00 to 4:00 and 8:00 to 10:00 when right angles are formed three times during each period.

James Alarie also sent in an answer of 46 times if you used a 24-hour clock as used by hospitals and the military.

Correctly solved by:

1. Mary Murtishaw	Cabot, Arkansas
2. James Alarie	Flint, Michigan

Send any comments or questions to: David Pleacher