Gillian spent $288 to buy some boxes of banana and chocolate chip cupcakes. Each box of banana cupcakes cost $9 and each box of chocolate chip cupcakes cost $12. The banana cupcakes were packed in boxes of 5 cupcakes each and the chocolate chip cupcakes were packed in boxes of 4 cupcakes each. She bought an equal number of banana cupcakes and chocolate chip cupcakes.
(a) How many boxes of banana cupcakes did she buy?
(b) How many boxes of chocolate chip cupcakes did she buy?
(a)
Total number of banana cupcakes and chocolate chip cupcakes is the same.

LCM of 5 and 4 = 20

Number of boxes for 20 banana cupcakes
= 20 ÷ 5
= 4

Number of boxes for 20 chocolate chip cupcakes
= 20 ÷ 4
= 5

1 set = 4 boxes of banana cupcakes and 5 boxes of chocolate chip cupcakes

Cost of 1 set
= 4 x 9 + 5 x 12
= 36 + 60
= $96

Number of sets
= 288 ÷ 96
= 3

Boxes of banana cupcakes
= 3 x 4
= 12

(b)
Boxes of chocolate chip cupcakes
= 3 x 5
= 15

Answer(s): (a) 12; (b) 15