The advertisement shows the cost of buying files from a bookstore.
- Eva bought 17 files. How much did she pay?
- Rael bought 100 files. How much did he pay?
(a)
Number of sets of 15 files
= 17 ÷ 15
= 1 r 2
Cost of first 15 files
= 15 x 3.10
= $46.50
Cost of the next 2 files
= 2 x 2.90
= $5.80
Amount that Eva paid
= 46.50 + 5.80
= $52.30
(b)
Number of files that was not part of the first 15 files
= 100 - 15
= 85
Cost of first 15 files = $46.50
Cost of the next 85 files
= 85 x 2.90
= $246.50
Total cost of 100 files before an additional discount of 7% is applied
= 46.50 + 246.50
= $293
Amount that Rael paid in percent after an additional discount of 7% is applied
= 100% - 7%
= 93%
100% of the total cost of 100 files = 293
1% of the total cost of 100 files = 293 ÷ 100 = 2.93
93% of the total cost of 100 files = 93 x 2.93 = 272.49
Amount that Rael paid = $272.49
Answer(s): (a) $52.30; (b) $272.49
