Higher November 2021 Paper 3 Q11
11 Erik thinks of a prime number between 20 and 30
His number is \(x\)% of 125
Work out one possible value of \(x\). [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| 23 or 29 | B1 | implied by correct answer |
| \(\dfrac{23}{125}\) \((\times 100)\) or \(\dfrac{29}{125}\) \((\times 100)\) or \(\dfrac{\text{their number}}{125}\ (\times 100)\) or their number = \(\dfrac{125x}{100}\) | M1 | oe their number can be any integer value |
| 18.4 or 23.2 or correct evaluation of their number as a percentage of 125 | A1ft | ft B0M1 oe their number must be an integer [20, 30] or any prime number |
Additional guidance
| 18.4 or 23.2 | B1M1A1 |
| 18.4 and 23.2 | B1M1A1 |
| 23 or 29 must be clearly indicated as their prime number | |
| Any integer [20, 30] used can score B0M1A1ft eg \(25 \div 125 \times 100\) with answer 20 | B0M1A1ft |
| Any prime number used can score B0M1A1ft eg \(7 \div 125 \times 100\) with answer 5.6 | B0M1A1ft |
| 24% of 125 is 30 with answer 24 | B0M1A1ft |
| 29% of 125 is 36.25 (36.25 is not an integer) | B1M0A0ft |
| 28% of 125 is 35 with answer 28 (35 is an integer out of range) | B0M1A0ft |
| 28% of 125 is 35 scores M1 (35 is an integer) | |
| 25% of 125 is 31.25 scores M0 (31.25 is not an integer) |