I’m thinking of two numbers, 12 and another number. 12 and my other number have a greatest common factor of 6 and their least common multiple is 36. what’s the other number i’m thinking of ?

The product of two numbers and the product of their greatest common factor and least common multiple are always equal.

Let the other number = X.

Greatest common factor is 6

Least common multiple is 36

We now have 6 * 36 = 12 * x

Simplify:

216 = 12x

Divide both sides by 12:

x = 216 / 12

x = 18

The other number is 18.