There are $99$ $4-3 = 33$-multiples of $3$ less than $100$.  $3$ of them are one-digit numbers: $3$, $6$ and $9$.  Hence there are $30$ $2$-digit multiples of $3$.  Similarly, there are $96 + 6 -1 = 16 -1 = 15$ $2$-digit multiples of $6$.  Hence, the answer is 30 - 15 = \textbf{15.}  Answer： \textbf{(B)} 
How many two-digit numbers are divisible by $3$ but not by $6$? 

[A] $$14$$ 
[B] $$15$$ 
[C] $$17$$ 
[D] $$30$$ 
[E] None of the above 