Question

Taking $\mathrm{U}=\left[1,5\right],\mathrm{A}=\left\{\mathrm{x}/\mathrm{x}\in \mathrm{N},{\mathrm{x}}^2-6\mathrm{x}+5=0\right\},\mathrm{A}\text{'}=?$

• A. $\left\{1,5\right\}$
• B. $\left(1,5\right)$
• C. $\left[1,5\right]$
• D. $\left[-1,-5\right]$

Answer 1

The correct option is B

$\left(1,5\right)$

Explanation for the correct option:

Determining the value of $\mathrm{A}\text{'}$.

Firstly we have to find the roots of the equation, $x^2-6x+5=0$

By solving we get, $x=5,1$

So $\mathrm{A}$ contains,

$\mathrm{A}=\left\{1,5\right\}$

therefore, $\mathrm{A}\text{'}$ contains

$\mathrm{A}\text{'}=\left(1,5\right)\left(\mathrm{Elements}\mathrm{Other}\mathrm{than}\mathrm{that}\mathrm{in}\mathrm{A}\right)$

Hence, the correct answer is option (B).