$\displaystyle { \left( {8 \over 33} + {13 \over 22} \right) : \frac 5 {18}=\left( {16 \over 66} + {39 \over 66} \right) : \frac 5 {18}}$ 

$\displaystyle { {55 \over 66} : \frac {5}{18}= {55 \over 66} * \frac {18} {5} = {11\over 11} \cdot {3\over 1} =3 }$