At a stationery kiosk, Aaron paid $17 for 1 story book and 3 colouring books. The story book cost $8 more than the total cost of all the colouring books.
- How much did 1 story book cost?
- How much did 1 colouring book cost?
(a)
Cost of 3 colouring books = 1 u
Cost of 1 story book = 1 u + 8
Total cost of 3 colouring books and 1 story book
= 1 u + 1 u + 8
= 2 u + 8
2 u + 8 = 17
2 u = 17 - 8
2 u = 9
1 u = 9 ÷ 2 = 4.50
Cost of 1 story book
= 1 u + 8
= 4.50 + 8
= $12.50
(b)
Cost of 3 colouring books = $4.50
Cost of 1 colouring book
= 4.50 ÷ 3
= $1.50
Answer(s): (a) $12.50; (b) $1.50