The advertisement shows the cost of buying pencils from a stationery kiosk.
- Usha bought 28 pencils. How much did she pay?
- Xavier bought 80 pencils. How much did he pay?
(a)
Number of sets of 15 pencils
= 28 ÷ 15
= 1 r 13
Cost of first 15 pencils
= 15 x 4.10
= $61.50
Cost of the next 13 pencils
= 13 x 3.70
= $48.10
Amount that Usha paid
= 61.50 + 48.10
= $109.60
(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 3.70
= $240.50
Total cost of 80 pencils before an additional discount of 9% is applied
= 61.50 + 240.50
= $302
Amount that Xavier paid in percent after an additional discount of 9% is applied
= 100% - 9%
= 91%
100% of the total cost of 80 pencils = 302
1% of the total cost of 80 pencils = 302 ÷ 100 = 3.02
91% of the total cost of 80 pencils = 91 x 3.02 = 274.82
Amount that Xavier paid = $274.82
Answer(s): (a) $109.60; (b) $274.82
