If a*b denotes the greatest common divisor of a and b, then ((12*15)*(18*24)) = ?  Choose one: A) 24 B) 12 C) 6 D) 4 E) 3
The greatest common divisor of 12 and 15 is 3. Hence 12*15 = 3 (note that * here denotes the function not multiplication).   The greatest common divisor of 18 and 24 is 6. Hence 18*24 = 6.   Hence ((12*16)*(18*24)) = 3*6.   The greatest common divisor of 3 and 6 is 3.   Answer; 3.
<result>E</result>
If a*b denotes the greatest common divisor of a and b, then ((12*15)*(18*24)) = ?