Question

James says that 12 is a common factor of 3 and 4.june says that 12 is common multiple of 3 and 4.who is correct.

Answer 1

June is correct because 12 is a multiple of both 3 and 4.

Answer 2

June is correct. 

When you are dealing with factors, you have to think of what numbers multiply to get the number I see.
Let's say the number is 10. What numbers can be multiplied to get 10.
Well, there is 1, 10, 2, 5 so all of those numbers are factors of 10.

When you are dealing with multiples, you have to think of the opposite. If the question asks is 12 a multiple of 3 and 4, than you have to think...If I multiply a number by 3 could I get 12 and... If I multiply a number by 4 could I get 12. The answer is yes you could multiply 3 and 4 and 4 and 3 to get the number 12. That makes 12 a multiple.