SSC Sample Paper Mock Test-6 SSC CGL Tear-II Paper-1

  • question_answer
    \[\left( 1-\frac{1}{2} \right)\left( 1-\frac{1}{3} \right)\left( 1-\frac{1}{4} \right)...\left( 1-\frac{1}{n-1} \right)\left( 1-\frac{1}{n} \right)\]is equal to

    A)  \[\frac{1}{2n}\]

    B)  \[\frac{1}{5n}\]

    C)  \[\frac{1}{3n}\]

    D)  \[\frac{1}{n}\]

    Correct Answer: D

    Solution :

    Given expression  \[=\left( 1-\frac{1}{2} \right)\left( 1-\frac{1}{3} \right)\left( 1-\frac{1}{4} \right)...\left( 1-\frac{1}{n-1} \right)\left( 1-\frac{1}{n} \right)\] \[=\frac{1}{2}\times \frac{2}{3}\times \frac{3}{4}\times \frac{4}{5}\times ...\times \frac{n-2}{n-1}\times \frac{n-1}{n}=\frac{1}{n}\]


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