Problem solving

Question

Problem solving:

Justin cuts a 10 by 10 inch square cake into 2 by 2 inch pieces in 40 seconds. How long will it take Justin to cut a 16 by 16 inch square cake in 2 by 2 inch pieces?

Answer 1

To cut a 10x10 inch cake into 2x2 inch pieces requires 4 cuts of 10 inches each plus 4 cuts of 10 inches each.  That's 80 inches of cuts.  For 40 seconds, that's 0.5 sec per inch of cut.

 

There is time between cuts, but let's ignore that.

 

To cut a 16x16 inch cake into 2x2 inch pieces requires 7 cuts of 16 inches each plus 7 cuts of 16 inches each.  That's 224 inches of cuts.  At 0.5 sec per inch of cut, that's 112 seconds.

 

 

Answer 2

Justin cut 25 piece in 40 seconds.

How much time is needed to cut 64?

 

40 : 25 :: t : 64     proportion

25t = 40(64)

25t = 2560

t = 102.4