The expression $\frac{3^{2011}+3^{2011}}{3^{2010}+3^{2012}}$ is equal to
(A) $\frac{3}{5}$
(B) 1
(C) $\frac{9}{10}$
(D) $\frac{10}{3}$
(E) $\frac{2}{3}$
Since $3^{2011}=3^{1} \cdot 3^{2010}=3 \cdot 3^{2010}$ and $3^{2012}=3^{2} \cdot 3^{2010}=9 \cdot 3^{2010}$, then

$$
\frac{3^{2011}+3^{2011}}{3^{2010}+3^{2012}}=\frac{3 \cdot 3^{2010}+3 \cdot 3^{2010}}{3^{2010}+9 \cdot 3^{2010}}=\frac{3^{2010}(3+3)}{3^{2010}(1+9)}=\frac{3+3}{1+9}=\frac{6}{10}=\frac{3}{5}
$$

ANSWER: (A)