4400 Higher November 2007 Paper 4 Q17
17
(a) Find the Highest Common Factor of 72 and 90 (2)
(b) Find the Lowest Common Multiple of 72 and 90 (2)
| Scheme | Marks |
|---|---|
| \(72 = 2^3 \times 3^2\) and \(90 = 2 \times 3^2 \times 5\) or \(2 \times 3^2\) or 1,2,3,4,6,8,9,12,18, 24, 36,72 and 1,2,3,5,6,9,10,15,18,30,45,90 | M1 |
| 18 | A1 |
| (2) |
Notes
M1: Need not be products of powers; accept products or lists ie 2,2,2,3,3 and 2,3,3,5
Prime factors may be shown as factor trees
A1: cao
| Scheme | Marks |
|---|---|
| \(2^3 \times 3^2 \times 5\) or 72, 144, 216, 288, 360 and 90, 180, 270, 360 | M1 |
| 360 | A1 |
| (2) | |
| (4 marks) |
Notes
A1: cao