Higher November 2021 Paper 3 Q14
14 Phil sells ties.
He increases the original price of each tie by 10% to £13.20
A month later he announces a sale.
Phil says,
“The ties will be back to their original price, because each change was by 10%”
Is he correct?
Tick a box.
- Yes
- No
Show working to support your answer. [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| \(13.2 \times 0.9\) or 11.88 | M1 | oe |
| \(13.2(0) \div 1.1\) or 12 | M1 | oe |
| 11.88 and 12 and No | A1 | |
| Alternative method 2 | ||
| 1.1 or 0.9 seen | M1 | |
| \(1.1 \times 0.9\) or 0.99 | M1dep | |
| 0.99 and No | A1 | oe 1% decrease and No |
| Alternative method 3 | ||
| \(13.2 \times 0.9\) or 11.88 | M1 | |
| their \(11.88 \times 1.1\) or 13.068 | M1dep | |
| 13.068 and No | A1 | accept 13.07 or 13.06 |
Additional guidance
| \(12 \times 1.1 = 13.20,\ 13.2 \times 0.9 = 11.88\) and No | M1M1A1 |
| \(13.2 \times 1.1 = 14.52,\ 14.52 \times 0.9 = 13.068\) and No | M0M0A0 |