At a book shop, Josiah paid $18 for 1 colouring book and 2 story books. The colouring book cost $5 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 + 5
Total cost of 2 story books and 1 colouring book
= 1 u + 1 u + 5
= 2 u + 5
2 u + 5 = 18
2 u = 18 - 5
2 u = 13
1 u = 13 ÷ 2 = 6.50
Cost of 1 colouring book
= 1 u + 5
= 6.50 + 5
= $11.50
(b)
Cost of 2 story books = $6.50
Cost of 1 story book
= 6.50 ÷ 2
= $3.25
Answer(s): (a) $11.50; (b) $3.25