2. Questions Bank
  3. 10th Class
  4. Mathematics
  5. Related to Competitive Exam

10th Class Mathematics Related to Competitive Exam Question Bank Algebra

  • question_answer
    In n is a whole number greater than 1, then n \[\left( {{\text{n}}^{\text{2}}}\text{ }-\text{ 1} \right)\]is always divisible by

    A) 12                                            

    B) 12 and 24

    C) 24                          

    D)        36

    Correct Answer: A

    Solution :

    If \[n\] is a whole number, then least value of\[n=2,\,\,3,\,\,4,\,\,....\]                 \[{{n}^{2}}({{n}^{2}}-1)={{n}^{2}}(n+1)(n-1)\]                                   \[={{[4(2+1)(2-1)]}_{n=2}}\]                                   \[=12\] Hence, the given expression is always divisible by\[12\].


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