Bobby had some apricot cupcakes and strawberry cupcakes. ⁵₆ of the number of apricot cupcakes was equal to ¹₃ of the number of strawberry cupcakes. After Bobby made -12 more apricot cupcakes, the number of apricot cupcakes was ¹₅ of the number of strawberry cupcakes. How many cupcakes did he have altogether in the end?
Make the numerators the same. LCM of 5 and 1 is 5.

56 of apricot cupcakes = 1x53x5 of strawberry cupcakes

⁵₆ of apricot cupcakes = ⁵₁₅ of strawberry cupcakes

	Apricot cupcakes	Strawberry cupcakes	Total
Before	6 u	15 u
Change	+ -12
After	1x3 = 3 u	5x3 = 15 u	18 u

The number of strawberry cupcakes remains unchanged.  Make the number of strawberry cupcakes the same.  LCM of 5 and 15 is 15.

Number of more apricot cupcakes made
= 3 u - 6 u
= -3 u

-3 u = -12

1 u = -12 ÷ -3 = 4

Number of cupcakes that Bobby had in the end
= 3 u + 15 u
= 18 u
= 18 x 4
= 72

Answer(s): 72