Wendy spent $696 to buy some boxes of chocolate chip and vanilla biscuits. Each box of chocolate chip biscuits cost $6 and each box of vanilla biscuits cost $12. The chocolate chip biscuits were packed in boxes of 12 biscuits each and the vanilla biscuits were packed in boxes of 5 biscuits each. She bought an equal number of chocolate chip biscuits and vanilla biscuits.
(a) How many boxes of chocolate chip biscuits did she buy?
(b) How many boxes of vanilla biscuits did she buy?
(a)
Total number of chocolate chip biscuits and vanilla biscuits is the same.

LCM of 12 and 5 = 60

Number of boxes for 60 chocolate chip biscuits
= 60 ÷ 12
= 5

Number of boxes for 60 vanilla biscuits
= 60 ÷ 5
= 12

1 set = 5 boxes of chocolate chip biscuits and 12 boxes of vanilla biscuits

Cost of 1 set
= 5 x 6 + 12 x 12
= 30 + 144
= $174

Number of sets
= 696 ÷ 174
= 4

Boxes of chocolate chip biscuits
= 4 x 5
= 20

(b)
Boxes of vanilla biscuits
= 4 x 12
= 48

Answer(s): (a) 20; (b) 48