Higher November 2024 Paper 3 Q6
6 Three shops sell shirts.
At which shop is it cheapest to buy 6 shirts?
Show working to support your answer. [5 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1: Cost of six shirts | ||
| \(19(.00) \times 3\) or 57(.00) | M1 | oe shop A |
| \(12.4(0) \times 0.25\) or 3.1(0) or \(1 - 0.25\) or 0.75 | M1 | oe shop B implied by 9.3(0) |
| \((12.4(0) -\) their \(3.1(0)) \times 6\) or \(12.4(0) \times\) their \(0.75 \times 6\) or \(9.3(0) \times 6\) or 55.8(0) | M1dep | oe shop B dep on 2nd M |
| \(37.4(0) \times 1.5\) or 56.1(0) | M1 | oe shop C |
| B and 57(.00) and 55.8(0) and 56.1(0) | A1 | |
| Alternative method 2: Cost per shirt | ||
| \(19(.00) \div 2\) or 9.5(0) | M1 | oe shop A |
| \(12.4(0) \times 0.25\) or 3.1(0) or \(1 - 0.25\) or 0.75 | M1 | oe shop B implied by 9.3(0) |
| \(12.4(0) -\) their 3.1(0) or \(12.4(0) \times\) their 0.75 or 9.3(0) | M1dep | oe shop B dep on 2nd M |
| \(37.4(0) \times 1.5 \div 6\) or 9.35 | M1 | oe shop C |
| B and 9.5(0) and 9.3(0) and 9.35 | A1 | |
Additional guidance
Use the scheme which favours the student
Comparable costs for different quantities of shirts
| Shop | Cost of 1 | Cost of 2 | Cost of 3 | Cost of 6 |
|---|---|---|---|---|
| A | 9.5(0) | 19(.00) | 28.5(0) | 57(.00) |
| B | 9.3(0) | 18.6(0) | 27.9(0) | 55.8(0) |
| C | 9.35 | 18.7(0) | 28.05 | 56.1(0) |