\[Страница\ 95.\]
\[\boxed{\mathbf{11.}}\]
\[\frac{3}{5} \cdot \left( 1 - \frac{3}{8} \right) = \frac{3}{5} \cdot \frac{5}{8} = \frac{3}{8} - всех\ \]
\[денег\ выдали\ во\ второй\ раз.\]
\[20\ 000\ :\left( 1 - \frac{3}{8} - \frac{3}{8} \right) =\]
\[= 20\ 000\ :\frac{2}{8} = 20\ 000 \cdot 4 =\]
\[= 80\ 000\ рублей.\]
\[Ответ:80\ 000\ рублей.\]
\[\boxed{\mathbf{12.}}\]
\[\textbf{а)}\ 75\% = \frac{75}{100} = \frac{3}{4}\]
\[\textbf{б)}\ 50\% = \frac{50}{100} = \frac{1}{2}\]
\[\textbf{в)}\ 25\% = \frac{25}{100} = \frac{1}{4}\]
\[\textbf{г)}\ 12,5\% = \frac{125}{1000} = \frac{1}{8}\]
\[\textbf{д)}\ 10\% = \frac{10}{100} = \frac{1}{10}\]
\[\textbf{е)}\ 5\% = \frac{5}{100} = \frac{1}{20}\]
\[\textbf{ж)}\ 33\frac{1}{3}\% = \frac{100}{300} = \ \frac{1}{3}\]
\[\textbf{з)}\ 66\frac{2}{3}\% = \frac{200}{300} = \frac{2}{3}\]
\[\textbf{и)}\ 16\frac{2}{3}\% = \frac{50}{300} = \frac{1}{6}\]
\[к)\ 24\frac{1}{5}\% = \frac{121}{500}\]
\[\boxed{\mathbf{13.}}\]
\[\textbf{а)}\ 195\ :\frac{13}{15} = 195 \cdot \frac{15}{13} =\]
\[= 15 \cdot 15 = 225\]
\[Ответ:225.\]
\[\textbf{б)}\ 51\ :\frac{17}{23} = 51 \cdot \frac{23}{17} = 3 \cdot 23 =\]
\[= 69\]
\[Ответ:69.\]
\[\textbf{в)}\ 4\frac{1}{6}\ :\frac{5}{12} = \frac{25}{6} \cdot \frac{12}{5} = 5 \cdot 2 = 10\]
\[Ответ:10.\]