The advertisement shows the cost of buying notebooks from a book shop.
- Lucy bought 18 notebooks. How much did she pay?
- Oliver bought 100 notebooks. How much did he pay?
(a)
Number of sets of 15 notebooks
= 18 ÷ 15
= 1 r 3
Cost of first 15 notebooks
= 15 x 2.10
= $31.50
Cost of the next 3 notebooks
= 3 x 1.90
= $5.70
Amount that Lucy paid
= 31.50 + 5.70
= $37.20
(b)
Number of notebooks that was not part of the first 15 notebooks
= 100 - 15
= 85
Cost of first 15 notebooks = $31.50
Cost of the next 85 notebooks
= 85 x 1.90
= $161.50
Total cost of 100 notebooks before an additional discount of 4% is applied
= 31.50 + 161.50
= $193
Amount that Oliver paid in percent after an additional discount of 4% is applied
= 100% - 4%
= 96%
100% of the total cost of 100 notebooks = 193
1% of the total cost of 100 notebooks = 193 ÷ 100 = 1.93
96% of the total cost of 100 notebooks = 96 x 1.93 = 185.28
Amount that Oliver paid = $185.28
Answer(s): (a) $37.20; (b) $185.28
