How much flour is needed to make 90 cookies?

Question

A cookie recipe for 60 cookies calls for 4 cups of flour how much flour is needed to make 90 cookies?

Answer 1

60 : 4 :: 90 : c   proportion

60c = 4(90)       product means/extremes

60c = 360

c = 6

 

Or

 

90 is 1.5 times 60, therefore you need 1.5 times 4 cups.