Ответ:

\(3\frac{3}{4}=\frac{15}{4}\), \(1\frac{5}{6}=\frac{11}{6}\).

\(\left(\frac{15}{4}-\frac{11}{6}\right)\cdot36=\left(\frac{45}{12}-\frac{22}{12}\right)\cdot36=\frac{23}{12}\cdot36=69\).

Ответ: 69.