Zara paid $450 for some biscuits and puffs. The ratio of the boxes of biscuits to the boxes of puffs was 2 : 5. Each box of biscuits cost $6 more than each box of puffs. She paid $150 more for the biscuits than the puffs. What was the price of each box of biscuits?
(a)
Total amount that the puffs cost
= (450 - 150) ÷ 2
= 300 ÷ 2
= $150

Total amount that the biscuits cost
= 150 + 150
= $300

Number of sets of biscuits = 2
Number of sets of puffs = 5

Cost of 1 set of biscuits
= 300 ÷ 2
= $150

Cost of 1 set of puffs
= 150 ÷ 5
= $30

Amount that 1 set of biscuits cost more than 1 set of puffs
= 150 - 30
= $120

Number of boxes of biscuits in 1 set
= 120 ÷ 6
= 20

Price of each box of biscuits
= 150 ÷ 20
= $7.50

Answer(s): $7.50