At a stationery shop, Victoria paid $18 for 1 colouring book and 2 story books. The colouring book cost $7 more than the total cost of all the story books.
- How much did 1 colouring book cost?
- How much did 1 story book cost?
(a)
Cost of 2 story books = 1 u
Cost of 1 colouring book = 1 u + 7
Total cost of 2 story books and 1 colouring book
= 1 u + 1 u + 7
= 2 u + 7
2 u + 7 = 18
2 u = 18 - 7
2 u = 11
1 u = 11 ÷ 2 = 5.50
Cost of 1 colouring book
= 1 u + 7
= 5.50 + 7
= $12.50
(b)
Cost of 2 story books = $5.50
Cost of 1 story book
= 5.50 ÷ 2
= $2.75
Answer(s): (a) $12.50; (b) $2.75