19\(\frac{1}{2}\) : \(\left\)\(3\frac{1}{2} - 1\frac{11}{20} \right\) - \(\frac{111}{200}\) : \(\frac{3}{20}\)

Решение:

Выполним действия по порядку:

1. 
   \[ 3\frac{1}{2} - 1\frac{11}{20} = \frac{7}{2} - \frac{31}{20} = \frac{70}{20} - \frac{31}{20} = \frac{39}{20} \]
   
2. 
   \[ 19\frac{1}{2} : \frac{39}{20} = \frac{39}{2} : \frac{39}{20} = \frac{39}{2} \cdot \frac{20}{39} = 10 \]
   
3. 
   \[ \frac{111}{200} : \frac{3}{20} = \frac{111}{200} \cdot \frac{20}{3} = \frac{37}{10} \]
   
4. 
   \[ 10 - \frac{37}{10} = \frac{100}{10} - \frac{37}{10} = \frac{63}{10} = 6.3 \]
   

Ответ: 6.3