Friday, February 3, 2012

Clock Geometry

For a Friday puzzle, another one lifted from William Poundstone's recent "Are You Smart Enough To Work at Google":

At 3:15, what is the angle formed between the minute hand and hour hand on an analog (regular) clock?
(if the answer seems immediately obvious to you, you likely have the wrong answer)

I'll be giving the correct answer in the comments section below.

1 comment:

"Shecky Riemann" said...

ANSWER: At 3:15 the minute hand will be pointing due east toward the 3. The hour hand however will have already moved one-quarter of the way between the 3 and 4. The entire 3 to 4 interval is 1/12th of the full 360 degree circle, or 30 degrees. 1/4 of that (30 degrees) is then 7.5 degrees, the correct answer.