The advertisement shows the cost of buying files from a bookstore.
- Marion bought 18 files. How much did she pay?
- Simon bought 80 files. How much did he pay?
(a)
Number of sets of 15 files
= 18 ÷ 15
= 1 r 3
Cost of first 15 files
= 15 x 4.50
= $67.50
Cost of the next 3 files
= 3 x 4.10
= $12.30
Amount that Marion paid
= 67.50 + 12.30
= $79.80
(b)
Number of files that was not part of the first 15 files
= 80 - 15
= 65
Cost of first 15 files = $67.50
Cost of the next 65 files
= 65 x 4.10
= $266.50
Total cost of 80 files before an additional discount of 9% is applied
= 67.50 + 266.50
= $334
Amount that Simon paid in percent after an additional discount of 9% is applied
= 100% - 9%
= 91%
100% of the total cost of 80 files = 334
1% of the total cost of 80 files = 334 ÷ 100 = 3.34
91% of the total cost of 80 files = 91 x 3.34 = 303.94
Amount that Simon paid = $303.94
Answer(s): (a) $79.80; (b) $303.94
