\[1)\ M = 18 + 6 + 36 = 60\ (кг) -\]
\[общая\ масса\ сплава.\]
\[2)\ \frac{18}{60} \bullet 100\% = \frac{180}{6}\% = 30\% -\]
\[цинка.\]
\[3)\ \frac{6}{60} \bullet 100\% = \frac{100}{10}\% = 10\% -\]
\[олова.\]
\[4)\ \frac{36}{60} \bullet 100\% = \frac{600}{10}\% = 60\% -\]
\[меди.\]
\[Ответ:\ \ 30\%;\ 10\%;\ 60\%.\]