Emma spent $174 to buy some boxes of chocolate chip and cranberry croissants. Each box of chocolate chip croissants cost $9 and each box of cranberry croissants cost $12. The chocolate chip croissants were packed in boxes of 10 croissants each and the cranberry croissants were packed in boxes of 6 croissants each. She bought an equal number of chocolate chip croissants and cranberry croissants.
(a) How many boxes of chocolate chip croissants did she buy?
(b) How many boxes of cranberry croissants did she buy?
(a)
Total number of chocolate chip croissants and cranberry croissants is the same.

LCM of 10 and 6 = 30

Number of boxes for 30 chocolate chip croissants
= 30 ÷ 10
= 3

Number of boxes for 30 cranberry croissants
= 30 ÷ 6
= 5

1 set = 3 boxes of chocolate chip croissants and 5 boxes of cranberry croissants

Cost of 1 set
= 3 x 9 + 5 x 12
= 27 + 60
= $87

Number of sets
= 174 ÷ 87
= 2

Boxes of chocolate chip croissants
= 2 x 3
= 6

(b)
Boxes of cranberry croissants
= 2 x 5
= 10

Answer(s): (a) 6; (b) 10