Foundation November 2017 Paper 2 Q17
17 Andrew is thinking of a number.
- It is between 1 and 150.
- It is one more than a square number.
- It is three less than a cube number.
- It is not a prime number.
What is Andrew’s number?
You must show all your reasoning. [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 122 with justification showing 121 or \(11^2 + 1\) and 125 or \(5^3 - 3\) | 4 | B3 for answer 122 OR M1 for at least 5 square numbers (or 5 square numbers + 1) isw M1 for at least 3 cube numbers (or 3 cube numbers – 3) isw M1 for reducing their list to non-primes If 0 scored, SC1 for answer 5 or 17 or 37 or 61 or 101 | 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144 2, 5, 10, 17, 26, 37, 50, 65, 82, 101, 122, 145 1, 8, 27, 64, 125 5, 24, 61, 122 Implied by any non-prime answer less than 150 |