## Thinking Mathematically (6th Edition)

$\frac{1}{4}$
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 are 13 diamonds, so there is a total of 13 favorable outcomes. P(E) = $\frac{13}{52}$ = $\frac{1}{4}$