MathNet 2016-part-05 — 184 problems (EN–VI) Question 124

In $\triangle ABC$, $\hat{A} = 120^\circ$ and $\hat{B}$ is five times $\hat{C}$. The number of degrees in $\hat{C}$ is
(A) 10 (B) 12 (C) 15 (D) 18 (E) 20