The Hourglasses

Algebra Level 2

Peter has 2 hourglasses,one that has a duration time of 7 min. and one with 9 min. When the sand runs out,Peter will have to turn the hourglasses over again.Now,Peter wants to bake cookies at exactly 11 min.

What is the minimum number of times that he must turn the smaller hourglass??

×

Problem Loading...

Note Loading...

Set Loading...