If a*b denotes the greatest common divisor of a and b, then ((20*16)*(18*24)) = ? Answers.
A) 24
B) 12
C) 6
D) 4
E) 2

Rationale: "the greatest common divisor of 20 and 16 is 4 . hence 20 * 16 = 4 ( note that * here denotes the function not multiplication ) . the greatest common divisor of 18 and 24 is 6 . hence 18 * 24 = 6 . hence ( ( 20 * 16 ) * ( 18 * 24 ) ) = 4 * 6 . the greatest common divisor of 4 and 6 is 2 . answer ; e ."
Answer: E