Question

If one root of the equation $x^{2}-\lambda x+12=0$ is even prime while $x^{2}+\lambda x+\mu=0$ has equal roots, then $\mu$ is equal to

• A. 8
• B. 16
• C. 24
• D. 32

Answer 1

Answer: (B)

We know that, only even prime is $2 .$
Then, $(2)^{2}-\lambda(2)+12=0 $
$\Rightarrow \lambda=8 \ldots$...(i)
and $x^{2}+\lambda x+\mu=0$
has equal roots.
$\therefore \lambda^{2}-4 \mu=0$
or$(8)^{2}-4 \mu=0$ [from Eq. (i)]
$\therefore \mu=16$