Foundation November 2017 Paper 1 Q15
15
5% of a number is 31
1% of the same number is 6.2
Work out 13% of the number. [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| Method for finding a percentage beyond 5% or 1% | M1 | eg \(6.2 \div 2\) or 3.1 (0.5%) \(31 + 6.2\) or 37.2 (6%) \(31 \times 2\) or 62 (10%) \(6.2 + 6.2\) or 12.4 (2%) \(31 \times 3\) or 93 (15%) \(6.2 \times 3\) or 18.6 (3%) |
| Fully correct method that would lead to the correct answer | M1dep | eg their \(93 -\) their 12.4 (their 3.1 + their 37.2) \(\times\) 2 their 62 + their 18.6 |
| 80.6 | A1 | |
| Alternative method 2 | ||
| \(6.2 \times 13\) or \(62 \times 13\) | M1 | may be implied |
| \(10 \times 6.2 + 3 \times 6.2\) or \(62 + 18.6\) or \(6 \times 13 + 0.2 \times 13\) or \(78 + 2.6\) or digits 806 other than 80.6 | M1dep | From traditional method their 186 + their 620 or their 26 + their 780 at least one correct and placeholder of zero correct or implied From grid method their 600 + their 20 + their 180 + their 6 at least three correct From Chinese / Napier’s bones method at least three values correct from (0)/6, (0)/2, (0)/6 and 1/8 and then appropriate diagonal adding |
| 80.6 | A1 | |
Additional guidance
In all cases, accept repeated addition for multiplication
eg accept 31 + 31 for \(2 \times 31\)
Ignore a % sign after 80.6