The advertisement shows the cost of buying pencils from a shop.
- Ivory bought 19 pencils. How much did she pay?
- Julian bought 80 pencils. How much did he pay?
(a)
Number of sets of 15 pencils
= 19 ÷ 15
= 1 r 4
Cost of first 15 pencils
= 15 x 4.10
= $61.50
Cost of the next 4 pencils
= 4 x 3.90
= $15.60
Amount that Ivory paid
= 61.50 + 15.60
= $77.10
(b)
Number of pencils that was not part of the first 15 pencils
= 80 - 15
= 65
Cost of first 15 pencils = $61.50
Cost of the next 65 pencils
= 65 x 3.90
= $253.50
Total cost of 80 pencils before an additional discount of 4% is applied
= 61.50 + 253.50
= $315
Amount that Julian paid in percent after an additional discount of 4% is applied
= 100% - 4%
= 96%
100% of the total cost of 80 pencils = 315
1% of the total cost of 80 pencils = 315 ÷ 100 = 3.15
96% of the total cost of 80 pencils = 96 x 3.15 = 302.40
Amount that Julian paid = $302.40
Answer(s): (a) $77.10; (b) $302.40
