JEE Main & Advanced AIEEE Solved Paper-2013

  • question_answer
    Let A and B be two sets containing 2 elements and 4 elements respectively. The number of subsets of\[A\times B\] having 3 or more elements is:     AIEEE Solevd Paper-2013

    A) 256        

    B)                        220                        

    C) 219                        

    D)        211

    Correct Answer: C

    Solution :

    \[A=\{x,\text{ }y\}\] \[B=\{a,\text{ }b,\text{ }c,\text{ }d\}\] \[A\times B\]having\[2\times 4=8\] elements Total subsets of\[A\times B\]is\[{{2}^{8}}=256\] \[\therefore \]Total no. of subsets of\[A\times B\]having 3 or more elements \[=256-\left( \underset{\begin{smallmatrix}  null \\  set \end{smallmatrix}}{\mathop{1}}\,+\underset{\begin{smallmatrix}  \sin gle\,ton \\  set \end{smallmatrix}}{\mathop{8}}\,+\underset{\begin{smallmatrix}  subset\,having \\  2\,elements \end{smallmatrix}}{\mathop{^{8}{{C}_{2}}}}\, \right)\] \[=256-1-8-28=219\]


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