2015 Cayley Problem 8

Violet has one-half of the money she needs to buy her mother a necklace. After her sister gives her \$30, she has three-quarters of the amount she needs. Violet's father agrees to give her the rest. The amount that Violet's father will give her is

\textbf{(A)}\ \$7.50\quad \textbf{(B)}\ \$15\quad \textbf{(C)}\ \$22.50\quad \textbf{(D)}\ \$30\quad \textbf{(E)}\ \$120

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Cayley contests here.