The advertisement shows the cost of buying pens from a bookstore.
- Gabby bought 21 pens. How much did she pay?
- Oliver bought 50 pens. How much did he pay?
(a)
Number of sets of 15 pens
= 21 ÷ 15
= 1 r 6
Cost of first 15 pens
= 15 x 3.90
= $58.50
Cost of the next 6 pens
= 6 x 3.70
= $22.20
Amount that Gabby paid
= 58.50 + 22.20
= $80.70
(b)
Number of pens that was not part of the first 15 pens
= 50 - 15
= 35
Cost of first 15 pens = $58.50
Cost of the next 35 pens
= 35 x 3.70
= $129.50
Total cost of 50 pens before an additional discount of 8% is applied
= 58.50 + 129.50
= $188
Amount that Oliver paid in percent after an additional discount of 8% is applied
= 100% - 8%
= 92%
100% of the total cost of 50 pens = 188
1% of the total cost of 50 pens = 188 ÷ 100 = 1.88
92% of the total cost of 50 pens = 92 x 1.88 = 172.96
Amount that Oliver paid = $172.96
Answer(s): (a) $80.70; (b) $172.96
