CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2004

  • question_answer
    The sum of\[{{15}^{2}}+{{16}^{2}}+{{17}^{2}}+.....+{{30}^{2}}\]is equal to:

    A)  8840                                     

    B)  8440

    C)  8540                     

    D)         8450

    E)  8000

    Correct Answer: B

    Solution :

    \[{{15}^{2}}+{{16}^{2}}+{{17}^{2}}......+{{30}^{2}}\] \[={{1}^{2}}+{{2}^{2}}+...+{{30}^{2}}-({{1}^{2}}+{{2}^{2}}+....+{{14}^{2}})\] \[=\frac{30(31)(61)}{6}-\frac{14(15)(29)}{6}\] \[=\frac{56730-6090}{6}=8440\]


You need to login to perform this action.
You will be redirected in 3 sec spinner