Menu
Home / Arithmetic Aptitude / Numbers :: Discussion

Discussion :: Numbers

  1. The sum of how many terms of the series 6 + 12 + 18 + 24 + ... is 1800 ?

    2. A.

    16
    B.

    24
    C.

    20
    D.

    18
    E.

    22

    View Answer

    Workspace

    View Answer

    Answer : Option B

    Explanation :

    This is an A.P. in which a = 6, d = 6 and Sn = 1800

      Then,    \(\frac { n } { 2 } \)    [2a + (n - 1)d] = 180

     3n (n + 1) = 1800

     n(n + 1) = 600

     n2 + n - 600 = 0

     n2 + 25n - 24n - 600 = 0

     n(n + 25) - 24(n + 25) = 0

     (n + 25)(n - 24) = 0

     n = 24

    Number of terms = 24.

Write your comments here:

Be The First To Comment