\[\boxed{\mathbf{1239}\mathbf{.}}\]
\[\text{x\ }и\ y - данные\ числа:\]
\[x + y = 1100\]
\[y = 1100 - x.\]
\[Составим\ равенство\ по\ \]
\[условию:\]
\[x \bullet \frac{6}{100} = y \bullet \frac{5}{100}\]
\[\frac{3}{50}x = \frac{1}{20}y\]
\[y = \frac{3}{50}x \bullet \frac{20}{1} = \frac{60}{50}x = \frac{6}{5}\text{x.}\]
\[Значение\ наибольшего\ числа:\]
\[1100 - x = \frac{6}{5}x\]
\[5500 - 5x = 6x\]
\[11x = 5500\]
\[x = \frac{5500}{11} = 500;\]
\[y = \frac{6}{5} \bullet 500 = 6 \bullet 100 = 600.\]
\[Ответ:\ \ 600.\]