The number represented by $\square$ so that $\frac{1}{2}+\frac{1}{4}=\frac{\square}{12}$ is
(A) 3
(B) 12
(C) 9
(D) 6
(E) 15

Part B: Each correct answer is worth 6.
Solution 1

Evaluating using a denominator of $12, \frac{1}{2}+\frac{1}{4}=\frac{6}{12}+\frac{3}{12}=\frac{9}{12}$ and so the number represented by $\square$ is 9 .

Solution 2

Since $\frac{1}{2}+\frac{1}{4}=\frac{2}{4}+\frac{1}{4}=\frac{3}{4}$ and $\frac{3}{4}=\frac{9}{12}$, then $\frac{1}{2}+\frac{2}{4}=\frac{9}{12}$.

The number represented by $\square$ is 9 .

ANswer: (C)