Question

What is the GCF of the numbers, 36, 14, 21?

Answer 1

`GCF = 1`

Explanation:

The quickest way to work this out is to know the times tables!

Write each number as the product of its prime factors

`color(white)(xxxx)36 = 2xx2xx3xx3`
`color(white)(xxxx)14 = 2color(white)(xxxxxxxxx)xx7`
`color(white)(xxxx)21= color(white)(xxx.xx)3color(white)(xx.x)xx7`

There is no prime factor which is a common factor.

Therefore the `GCF = 1`