# Introduction to Statistics/Still confused?

${\displaystyle P(Queen\cup \spadesuit )=P(Queen)+P(\spadesuit )}$
We can draw a card from our two card deck. We are guaranteed to draw a spade, so ${\displaystyle P(\spadesuit )=1}$. Our chance of drawing a queen is 1 in 2, or ${\displaystyle {\tfrac {1}{2}}}$. Let's add everything together. ${\displaystyle P(Queen\cup \spadesuit )=1.5}$ or 150%. This obviously doesn't make sense.
${\displaystyle P(Queen\cup \spadesuit )=P(Queen)+P(\spadesuit )-P(Queen\cap \spadesuit )}$
${\displaystyle =0.5+1.0-0.5}$