Foundation June 2018 Paper 1R Q20
20 \(E = n^2 + n + 5\)
(a) Work out the value of \(E\) when \(n = 3\) (1)
Ali thinks that the value of \(E\) will be a prime number for any whole number value of \(n\).
(b) Is Ali correct?
You must give a reason for your answer. (2)
You must give a reason for your answer. (2)
| Scheme | Marks |
|---|---|
| 17 | B1 |
| (1) |
Notes
(The printed mark scheme gives no row for part (a); this answer is supplied: \(3^2 + 3 + 5 = 17\).)
| Scheme | Marks | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For example,
| M1 | ||||||||||||
| No + reason | A1 | ||||||||||||
| (2) | |||||||||||||
| (3 marks) |
Notes
M1: for evaluating \(E\) correctly for any value of \(n\)
A1: for No with \(E\) evaluated correctly as a non-prime number