[tex]10) \\ \\ \frac{3}{2 \times 5} + \frac{4}{5 \times 9} + \frac{5}{9 \times 14} + \frac{7}{14 \times 21} + \frac{11}{21 \times 32} = \\ \\ \frac{3}{10} + \frac{4}{45} + \frac{5}{126} + \frac{7}{294} + \frac{11}{672} = \\ \\ \frac{3}{10} + \frac{4}{45} + \frac{5}{26} + \frac{1}{42} + \frac{11}{672} = \\ \\ \frac{4725}{10080} ^{(315} = \frac{15}{32} [/tex]
