\[\boxed{\mathbf{545}.}\]
\[\left( 1 + \frac{p}{100} \right) \cdot N - прирост\]
\[\ жителей\ за\ год;\]
\[Y = v \cdot N \cdot \left( 1 + \frac{p}{100} \right)^{m} - через\ \]
\[\text{m\ }лет\ с\ нормой\ \text{v\ }\left( м^{3} \right)\ расхода\ \]
\[воды.\]
\[1)\ m = 3;v = 0,3;N = 250;\]
\[p = 8:\]
\[Y = 0,3 \cdot 250 \cdot \left( 1 + \frac{8}{100} \right)^{3} =\]
\[= 75 \cdot \left( \frac{108}{100} \right)^{3} = \frac{75 \cdot 27^{3}}{25^{3}} =\]
\[= \frac{59\ 049}{625} =\]
\[= 94,4784\ \left( м^{3} \right).\]
\[2)\ m = 4,5;\ \ v = 0,4;\ \]
\[\ N = 346;\ \ p = 10:\]
\[Y = 0,4 \cdot 346 \cdot \left( 1 + \frac{10}{100} \right)^{4,5} =\]
\[= \frac{2}{5} \cdot 346 \cdot \left( \frac{11}{10} \right)^{4,5} =\]
\[= 138,4 \cdot (1,1)^{4,5} =\]
\[= 138,4 \cdot 1,5355 \approx 212,5\ \left( м^{3} \right).\]