Higher November 2017 Paper 3 Q6
6 Show that 268 can be written as the sum of a power of 3 and a square number. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| Lists three from 3, 9, 27, 81, 243, 729 or lists three from 1, 4, 9, 16, …, 225, 256, 289 or correctly evaluating a power of 3 + a square number or correctly evaluating 268 − a power of 3 or correctly evaluating 268 − a square number | M1 | eg \(27 + 25 = 52\) or \(3^3 + 5^2 = 52\) eg \(268 - 27 = 241\) eg \(268 - 49 = 219\) |
| \(243 + 25\) or \(3^5 + 5^2\) | A1 | oe Addition sign must be seen in working or on answer line |
Additional guidance
| \(3^5, 5^2\) or \(3^5\) and \(5^2\) on answer line | M1A0 |
| \(268 - 243 = 25\) | M1A0 |
| 243, 25 or 243 and 25 on answer line | M1A0 |
| Beware of \(5^3 + 5^2\) |