Monday, June 23, 2008

9 Minutes

Question: You are given two hourglasses. One measures 4 minutes and one measures 7 minutes. How would you measure exactly 9 minutes?

Answer: we want to measure the 9 minutes right from the start.










































StepTime4 minute timer7 minute timer
10 minStartStart
24 minsFlip3 minutes left
37 mins1 minute leftFlipt
48 minsStopFlip (1 minute left)
59 minsStopStop