Matilda and Ellie divide a white wall in their bedroom in half, each taking half of the wall. Matilda paints half of her section red. Ellie paints one third of her section red. The fraction of the entire wall that is painted red is
(A) $\frac{5}{12}$
(B) $\frac{2}{5}$
(C) $\frac{2}{3}$
(D) $\frac{1}{6}$
(E) $\frac{1}{2}$

Part B: Each correct answer is worth 6.
Matilda and Ellie each take $\frac{1}{2}$ of the wall.

Matilda paints $\frac{1}{2}$ of her half, or $\frac{1}{2} \times \frac{1}{2}=\frac{1}{4}$ of the entire wall.

Ellie paints $\frac{1}{3}$ of her half, or $\frac{1}{3} \times \frac{1}{2}=\frac{1}{6}$ of the entire wall.

Therefore, $\frac{1}{4}+\frac{1}{6}=\frac{3}{12}+\frac{2}{12}=\frac{5}{12}$ of the wall is painted red.