In triangle $ABC,$ $\angle A = p + 2q$ degrees, $\angle B = 6p - 5q$ degrees, and $\angle C = 11p + 3q$ degrees. Find $p$ (in degrees).
The sum of the angles in a triangle is 180∘, so we have p+2q+6p−5q+11p+3q=180. Simplifying, we get 20p=180, so p=9.
