Answer
$\frac{1}{52}$
Work Step by Step
P(E) = $\frac{no.\ of\ outcomes\ in\ favor}{Total\ no\ of\ outcomes}$
There is a total of 52 cards, so there are 52 outcomes.
There is one ace of clubs, so there is a total of 1 favorable outcome.
P(E) = $\frac{1}{52}$