\(\displaystyle M = {2 \over {3.5}} + {2 \over {5.7}} + {2 \over {7.9}} + ..... + {2 \over {97.99}}\)
\(\displaystyle M= \left( {{1 \over 3} - {1 \over 5}} \right) + \left( {{1 \over 5} - {1 \over 7}} \right) \)\(\displaystyle + \left( {{1 \over 7} - {1 \over 9}} \right) + ... + \left( {{1 \over {97}} - {1 \over {99}}} \right) \)
\(\displaystyle M= {1 \over 3} - {1 \over {99}} = {{33} \over {99}} - {1 \over {99}} = {{32} \over {99}}.\)
