Five persons $A,B,C,D,E$ are contesting an election in which 3 persons are to be elected. If $C$ is elected unanimously, the probability that $D$ gets elected is

Given $C$ is selected

So $n\left(S\right)=4_{C_2}=6$

If $D$ is elected then we can select one other person

So $n\left(E\right)=3_{C_1}=3$

$P\left(E\right)=\frac{3}{6}=\frac{1}{2}$

$\therefore$ The probability that $D$  gets elected is $\frac{1}{2}$