The advertisement shows the cost of buying notebooks from a shop.
- Irene bought 24 notebooks. How much did she pay?
- Ken bought 100 notebooks. How much did he pay?
(a)
Number of sets of 15 notebooks
= 24 ÷ 15
= 1 r 9
Cost of first 15 notebooks
= 15 x 2.30
= $34.50
Cost of the next 9 notebooks
= 9 x 2.10
= $18.90
Amount that Irene paid
= 34.50 + 18.90
= $53.40
(b)
Number of notebooks that was not part of the first 15 notebooks
= 100 - 15
= 85
Cost of first 15 notebooks = $34.50
Cost of the next 85 notebooks
= 85 x 2.10
= $178.50
Total cost of 100 notebooks before an additional discount of 9% is applied
= 34.50 + 178.50
= $213
Amount that Ken paid in percent after an additional discount of 9% is applied
= 100% - 9%
= 91%
100% of the total cost of 100 notebooks = 213
1% of the total cost of 100 notebooks = 213 ÷ 100 = 2.13
91% of the total cost of 100 notebooks = 91 x 2.13 = 193.83
Amount that Ken paid = $193.83
Answer(s): (a) $53.40; (b) $193.83
