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    What is the value of ​21×3+23×5+25×7+⋯+299×101\frac{2}{1 \times 3} + \frac{2}{3 \times 5} + \frac{2}{5 \times 7} + \dots + \frac{2}{99 \times 101}1×3
    Question

    What is the value of
    21×3+23×5+25×7++299×101\frac{2}{1 \times 3} + \frac{2}{3 \times 5} + \frac{2}{5 \times 7} + \dots + \frac{2}{99 \times 101} ​

    A.

    101/102

    B.

    99/100

    C.

    100/101

    D.

    99/101

    Correct option is C

    Solution:

    21×3+23×5+25×7++299×101 113+1315+1517............+197199+1991101 \frac{2}{1 \times 3} + \frac{2}{3 \times 5} + \frac{2}{5 \times 7} + \dots + \frac{2}{99 \times 101}\\\ \\ 1 - \frac{1}{3} + \frac{1}{3} - \frac{1}{5} + \frac{1}{5} - \frac{1}{7} ............ + \frac{1}{97} - \frac{1}{99} +\frac{1}{99} - \frac{1}{101} \\\ \\

    =(11101) =100101= \left( 1 - \frac{1}{101} \right) \\\ \\ = \frac{100}{101}​​​

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