Một miếng bìa hình chữ nhật có nữa chu vi là $\frac{3}{4}m\frac{3}{4}m$ \frac{6}{11}$$ \frac{5}{11}$$ \frac{3}{7}$$ \frac{3}{5}$$ \frac{7}{9}$$ \frac{3}{5}$$ \frac{2}{9}$$ \frac{6}{7}$$ \frac{4}{7}$$ \frac{2}{5}$$ \frac{8}{15}$$ \frac{2}{11}$$ \frac{7}{15}$$ \frac{2}{11}$$ \frac{2\times 3\times 4}{3\times 4\times 5}$$ \frac{2}{3}$$ \frac{3}{4}$$ \frac{4}{5}$$ \frac{1}{5}$$ \frac{1\times 2\times 3\times 4}{5\times 6\times 7\times 8}$$ \frac{2}{5}$$ \frac{3}{4}$$ \frac{5}{6}$$ \frac{3}{4}$$ \frac{4}{5}$$ \frac{2}{3}$$ \frac{4}{5}$$ \frac{2}{7}$$ \frac{2}{3}$$ \frac{5}{2}$$ \frac{3}{4}$$ \frac{2}{5}$$ \frac{1}{2}$$ \frac{1}{3}$$ \frac{2}{9}$$ \frac{2}{9}$$ \frac{1}{2}$$ \frac{4}{5}$$ \frac{1}{2}$$ \frac{1}{3}$$ \frac{1}{2}$$ \frac{1}{3}$$ \frac{1}{4}$$ \frac{2}{7}$$ \frac{2}{3}$$ \frac{1}{7}$$ \frac{2}{5}$$ \frac{2}{5}$$ \frac{1}{2}$$ \frac{3}{5}$$ \frac{3}{5}$$ \frac{90}{100}$$ \frac{80}{100}$$ \frac{3}{4}$$ \frac{1}{5}$\frac{1}{2}\frac{1}{4}\frac{1}{3}\frac{1}{8}\frac{2}{8}\frac{1}{16}\frac{11}{12}\frac{6}{8}\frac{20}{50}\frac{1}{5}$ \frac{2}{5}$\frac{3}{4}x\frac{8}{9}x\frac{15}{16}x...x\frac{99}{100}=\frac{1x3}{2x2}x\frac{2x4}{3x3}x\frac{3x5}{4x4}x...x\frac{9x11}{10x10}=\frac{1x2x3x...x9}{2x3x4x...x10}x\frac{3x4x5x...x11}{2x3x4x...x10}=\frac{1}{10}x\frac{11}{2}=\frac{11}{20}$