Higher June 2018 Paper 1 Q21
21.
(a) How many different ways are there to arrange the letters A, B, C, D, E, F when each letter must be used exactly once? [2]
(b) Find the total number of these arrangements that start with either the letter A or the letter E. [2]
| Scheme | Marks | Comments |
|---|---|---|
| 720 | B2 | B1 for 6 × 5 × 4 × 3 × 2 (×1) or 6! or equivalent |
| Scheme | Marks | Comments |
|---|---|---|
| 240 | B2 | FT \(\dfrac{\text{‘their 720’}}{3}\) B1 for 2 × 5 × 4 × 3 × 2 (×1) or (6 × 5 × 4 × 3 × 2 (×1)) ÷ 3 or \(\dfrac{6!}{3}\) or 120 + 120 or \(\dfrac{2}{6}\times\)‘their 720’ or equivalent |
| (4) |