Find the sum of :

1/2 + 1/6+ 1/12+ 1/20+ 1/30 + 1/42+ 1/56 + 1/72 + 1/90 + 1/110 + 1/132

\frac{1}{2} + \frac{1}{6} + \frac{1}{12} + \frac{1}{20} + \frac{1}{30} + \frac{1}{42} + \frac{1}{56} + \frac{1}{72} + \frac{1}{90} + \frac{1}{110} + \frac{1}{132} = (1 - \frac{1}{2}) + (\frac{1}{2} - \frac{1}{3}) + (\frac{1}{3} - \frac{1}{4}) + (\frac{1}{4} - \frac{1}{5}) + (\frac{1}{5} - \frac{1}{6}) + (\frac{1}{6} - \frac{1}{7}) + (\frac{1}{7} - \frac{1}{8}) + (\frac{1}{8} - \frac{1}{9}) + (\frac{1}{9} - \frac{1}{10}) + (\frac{1}{10} - \frac{1}{11}) + (\frac{1}{11} - \frac{1}{12})

= 1 - \frac{1}{12} = \frac{11}{12}