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# If one root of the eqn., $x^2+px+12=0$ is 4, while the eqn., $x^2+px+q=0$ has equal roots, then the value of $q$=?

(A) $\large\frac{49}{4}$

(B) $\large\frac{4}{49}$

(C) $4$

(D) cannot be determined.

Given: One root of $x^2+px+12=0$ is 4
$\Rightarrow\:16+4p+12=0$
$\Rightarrow\:p=-7$
$x^2+px+q=0$ has equal roots.
$\Rightarrow\:p^2-4q=0$
$\Rightarrow\:49=4q$
$or\:q=\large\frac{49}{4}$