9) What is the smallest three-digit integer divisible by 3 and 13?
(A) 102
(B) 104
(C) 117
(D) 139
(E) none of the above.
9) The answer is (C).

Since 13 and 3 are prime numbers, their common multiples must be multiples of $13 \cdot 3=39$. The multiplication table of 39 starts with $39,78,117, \ldots$