The advertisement shows the cost of buying pens from a shop.
- Wendy bought 24 pens. How much did she pay?
- Mark bought 90 pens. How much did he pay?
(a)
Number of sets of 15 pens
= 24 ÷ 15
= 1 r 9
Cost of first 15 pens
= 15 x 2.10
= $31.50
Cost of the next 9 pens
= 9 x 1.90
= $17.10
Amount that Wendy paid
= 31.50 + 17.10
= $48.60
(b)
Number of pens that was not part of the first 15 pens
= 90 - 15
= 75
Cost of first 15 pens = $31.50
Cost of the next 75 pens
= 75 x 1.90
= $142.50
Total cost of 90 pens before an additional discount of 7% is applied
= 31.50 + 142.50
= $174
Amount that Mark paid in percent after an additional discount of 7% is applied
= 100% - 7%
= 93%
100% of the total cost of 90 pens = 174
1% of the total cost of 90 pens = 174 ÷ 100 = 1.74
93% of the total cost of 90 pens = 93 x 1.74 = 161.82
Amount that Mark paid = $161.82
Answer(s): (a) $48.60; (b) $161.82