11. (3 1/6 − 1 1/3) : 1 2/9 + (2 1/4 + 1 1/2) · 4/15

\(3\frac16-1\frac13=\frac{11}{6}\), поэтому \(\frac{11}{6}:1\frac29=\frac{11}{6}\cdot\frac9{11}=\frac32\).

\(2\frac14+1\frac12=\frac{15}{4}\), поэтому \(\frac{15}{4}\cdot\frac4{15}=1\).

\(\frac32+1=\frac52=2\frac12\).

Ответ: \(2\frac12\).