What is the largest number that has the multiples$168$ and $288$.

What is the greatest number that will divide $33$ and $45$ leaving $9$ as remainder in each case?

Use HCF to prove that the following numbers are co-primes.

$980$ and $1287$.

Use HCF to prove that the following numbers are coprimes.

$1365$ and $2057$.

Reduce the following fraction to the lowest term.

$\frac{306}{414}$

Reduce the following fraction to the lowest term.

$\frac{559}{989}$

Reduce the following fraction to the lowest term.

$\frac{611}{1457}$