\[Страница\ 109.\]
\[\boxed{\mathbf{13.}}\]
\[1\ сут.\ 8\ час = 24 + 8 =\]
\[= 32\ часа = 32 \cdot 60 =\]
\[= 1920\ мин.\]
\[1920\ :30 = 64\ :1\]
\[Ответ:\frac{64}{1}\ \ и\ \frac{1}{64}.\]
\[\boxed{\mathbf{14.}}\]
\[Ответ:1.\]
\[\boxed{\mathbf{15.}}\]
\[\textbf{б)}\ 5\ :1 = 500\%\]
\[\textbf{в)}\frac{7}{10} = \frac{70}{100} = 70\%\]
\[\textbf{г)}\ \frac{8}{20} = \frac{40}{100} = 40\%\]
\[\textbf{д)}\ 4\ :5 = \frac{4}{5} = \frac{80}{100} = 80\%\]
\[\textbf{е)}\ 18\ :5 = \frac{18}{5} = \frac{360}{100} = 360\%\ \]
\[\boxed{\mathbf{16.}}\]
\[\textbf{а)}\ 24 - 15 = 9\]
\[\textbf{б)}\frac{9}{24} = \frac{3}{8}\]
\[\textbf{в)}\frac{15}{9} = \frac{5}{3}\]
\[Ответ:а)\ 9;\ \ б)\ \frac{3}{8};\ \ в)\frac{5}{3}.\]