Intermediate June 2017 Unit 2 Q4
4. The diagram below shows a number machine.
Using the number machine, calculate:
(a) the INPUT when the OUTPUT is 36, [1]
(b) the OUTPUT when the INPUT is \(n\). [2]
| Scheme | Marks | Comments |
|---|---|---|
| 5 | B1 | Allow unambiguous indication of an answer of 5. |
| Scheme | Marks | Comments |
|---|---|---|
| 3 (n + 7) or 3 × (n + 7) or (n + 7)3 or (n + 7) ×3 or 3n + 21 | B2 | B1 for n + 7 × 3 OR 3 × n + 7 (bracket omitted). Penalise −1 any further incorrect work, e.g. ‘(n + 7) ×3 = n + 21’ is B2 – 1 = B1, ‘n + 7 × 3 = n + 21 is B1 – 1 = B0, ‘3 × n + 7 = 3n + 7’ is B1 – 1 = B0. |