Вычисляем:
\[\frac{11}{20} - \frac{12}{25} \cdot \frac{15}{16} = \frac{11}{20} - \frac{12 \cdot 15}{25 \cdot 16} = \frac{11}{20} - \frac{3 \cdot 3}{5 \cdot 4} = \frac{11}{20} - \frac{9}{20} = \frac{2}{20} = \frac{1}{10} = 0.1\]
Ответ: 0.1