JEE Main & Advanced Sample Paper JEE Main - Mock Test - 23

  • question_answer
    If x is a positive integer, then  is equal to

    A)  \[2\left( x! \right)\left( x4-1 \right)!\]   

    B)        \[2\left( x! \right)\left( x4-1 \right)!\left( x+2 \right)!\]

    C)  \[2\left( x! \right)\left( x+3 \right)!\]    

    D)  None of these

    Correct Answer: B

    Solution :

    [b]: Applying \[{{R}_{1}}\to {{R}_{2}}-{{R}_{1}},{{R}_{2}}\to {{R}_{3}}-{{R}_{2}}\] we get \[=2(x!)(x+1)!(x+2)!\](Expanding along \[{{C}_{1}}\]).

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