The greatest common factor of 16 and the positive integer n is 4, and the greatest common factor of n and 45 is 3. Which of the following could be the greatest common factor of n and 120? Choose the correct choice: A) 5 B) 8 C) 12 D) 24 E) 30
n includes the factors 2^2 (but not 2^3) and 3 (but not 3^2 or 5)   120 = 8*3*5   The GCF is   4*3= 
<gadget id="calculator">  4*3</gadget>
<output>12</output>
12.   The answer is 12.
<result>C</result>
The greatest common factor of 16 and the positive integer n is 4, and the greatest common factor of n and 45 is 3. Which of the following could be the greatest common factor of n and 120?