The advertisement shows the cost of buying files from a book shop.
- Roshel bought 23 files. How much did she pay?
- Fabian bought 60 files. How much did he pay?
(a)
Number of sets of 15 files
= 23 ÷ 15
= 1 r 8
Cost of first 15 files
= 15 x 2.70
= $40.50
Cost of the next 8 files
= 8 x 2.30
= $18.40
Amount that Roshel paid
= 40.50 + 18.40
= $58.90
(b)
Number of files that was not part of the first 15 files
= 60 - 15
= 45
Cost of first 15 files = $40.50
Cost of the next 45 files
= 45 x 2.30
= $103.50
Total cost of 60 files before an additional discount of 3% is applied
= 40.50 + 103.50
= $144
Amount that Fabian paid in percent after an additional discount of 3% is applied
= 100% - 3%
= 97%
100% of the total cost of 60 files = 144
1% of the total cost of 60 files = 144 ÷ 100 = 1.44
97% of the total cost of 60 files = 97 x 1.44 = 139.68
Amount that Fabian paid = $139.68
Answer(s): (a) $58.90; (b) $139.68