Determine whether the following number is prime or composite.

$649$

Determine whether the following number is prime or composite.

$721$

If $3$ and $5$ are factors of a number, then $15$ is also a factor of the number.

If $246$ is a multiple of a number, then $123$ is also a multiple of the number.

Complete the following factor tree.

Complete the following factor tree.

Write down the prime factorisation of $150$ and $60$.

Find the HCF and LCM of $150$ and $60$

Find the HCF of $12, 40$ and $45$.