The advertisement shows the cost of buying notebooks from a book shop.
- Yen bought 29 notebooks. How much did she pay?
- Brandon bought 70 notebooks. How much did he pay?
(a)
Number of sets of 15 notebooks
= 29 ÷ 15
= 1 r 14
Cost of first 15 notebooks
= 15 x 1.30
= $19.50
Cost of the next 14 notebooks
= 14 x 1.10
= $15.40
Amount that Yen paid
= 19.50 + 15.40
= $34.90
(b)
Number of notebooks that was not part of the first 15 notebooks
= 70 - 15
= 55
Cost of first 15 notebooks = $19.50
Cost of the next 55 notebooks
= 55 x 1.10
= $60.50
Total cost of 70 notebooks before an additional discount of 9% is applied
= 19.50 + 60.50
= $80
Amount that Brandon paid in percent after an additional discount of 9% is applied
= 100% - 9%
= 91%
100% of the total cost of 70 notebooks = 80
1% of the total cost of 70 notebooks = 80 ÷ 100 = 0.8
91% of the total cost of 70 notebooks = 91 x 0.8 = 72.80
Amount that Brandon paid = $72.80
Answer(s): (a) $34.90; (b) $72.80
