Two numbers are between 10 and 20. Their greatest common factor is 3. Which two numbers could they be?

Answer:12 and 15     or12 and 18    or 15 or 18Step-by-step explanation:The two numbers have to both be divisible by 3, since their greatest common factor is 3.  This only leaves..12, 15, or 18     (no other numbers between 10 and 20 are divisible by 3)The factors of 12 are: 2, 3, 4, 6, and 12The factors of 15 are: 3, 5, and 15The factors of 18 are: 2, 3, 6, 9, and 18All three numbers have 3 as a greatest common factor, so we have 3 pairs of numbers they could be...12 and 15     or12 and 18    or 15 or 18