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Discussion :: Numbers

  1.  

    \([1- \frac { 1 } { n }]\)+\([1- \frac {2 } { n}]\)+\([1- \frac { 3 } { n } ] \)+.... up to n terms=?

  2. A.

    \(\frac { 1 } { 2 }n\)

    B.

    \(\frac { 1 } { 2 }(n-1)\)

    C.

    \(\frac { 1 } { 2 }n(n-1)\)

    D.

    None of these

    View Answer

    Workspace

    Answer : Option B

    Explanation :

     

      ....to n terms
     Given  sum= (1+1+1+...to n terms)-\([\frac { 1 } { n} +\)   \(\frac {2} {n}+ \)   \(\frac {3 } { n }+\)    
     

     
           \(n- \frac {n } { 2 } \)\([\frac { 1 } { n } +1]\)

           

              \( n- \frac { n+1} { 2 } \)

             

             \( \frac { 1 } { 2 } (n-1)\)

       


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