Higher June 2023 Paper 3 Q5
5 \(A\) and \(B\) are numbers such that
\(A = 2^2 \times 3^4 \times 7\)
\(B = 3^2 \times 7^2\)
(a) Find the highest common factor (HCF) of \(A\) and \(B\). (1)
(b) Find the lowest common multiple (LCM) of \(A\) and \(B\). (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| 63 | B1 | for 63, accept \(3 \times 3 \times 7\) or \(3^2 \times 7\) |
| Answer | Mark | Mark scheme |
|---|---|---|
| 15 876 | M1 | for at least two of \(2^2\), \(3^4\), \(7^2\) or shows at least 3 multiples of 2268, eg 2268, 4536, 6804 and at least 3 multiples of 441, eg 441, 882, 1323 |
| A1 | for 15 876 or \(2^2 \times 3^4 \times 7^2\) oe |
Additional guidance
\((A =)\ 2^2 \times 3^4 \times 7\) scores 0 marks