The advertisement shows the cost of buying pens from a shop.
- Xylia bought 19 pens. How much did she pay?
- Neave bought 70 pens. How much did he pay?
(a)
Number of sets of 15 pens
= 19 ÷ 15
= 1 r 4
Cost of first 15 pens
= 15 x 1.50
= $22.50
Cost of the next 4 pens
= 4 x 1.10
= $4.40
Amount that Xylia paid
= 22.50 + 4.40
= $26.90
(b)
Number of pens that was not part of the first 15 pens
= 70 - 15
= 55
Cost of first 15 pens = $22.50
Cost of the next 55 pens
= 55 x 1.10
= $60.50
Total cost of 70 pens before an additional discount of 10% is applied
= 22.50 + 60.50
= $83
Amount that Neave paid in percent after an additional discount of 10% is applied
= 100% - 10%
= 90%
100% of the total cost of 70 pens = 83
1% of the total cost of 70 pens = 83 ÷ 100 = 0.83
90% of the total cost of 70 pens = 90 x 0.83 = 74.70
Amount that Neave paid = $74.70
Answer(s): (a) $26.90; (b) $74.70
