The advertisement shows the cost of buying notebooks from a store.
- Sabrina bought 27 notebooks. How much did she pay?
- Tom bought 70 notebooks. How much did he pay?
(a)
Number of sets of 15 notebooks
= 27 ÷ 15
= 1 r 12
Cost of first 15 notebooks
= 15 x 2.10
= $31.50
Cost of the next 12 notebooks
= 12 x 1.70
= $20.40
Amount that Sabrina paid
= 31.50 + 20.40
= $51.90
(b)
Number of notebooks that was not part of the first 15 notebooks
= 70 - 15
= 55
Cost of first 15 notebooks = $31.50
Cost of the next 55 notebooks
= 55 x 1.70
= $93.50
Total cost of 70 notebooks before an additional discount of 10% is applied
= 31.50 + 93.50
= $125
Amount that Tom paid in percent after an additional discount of 10% is applied
= 100% - 10%
= 90%
100% of the total cost of 70 notebooks = 125
1% of the total cost of 70 notebooks = 125 ÷ 100 = 1.25
90% of the total cost of 70 notebooks = 90 x 1.25 = 112.50
Amount that Tom paid = $112.50
Answer(s): (a) $51.90; (b) $112.50