Practice By Tag: Conditional Probability

1 . Let $X = \{1,2,3,\dots,10\}$. We choose, uniformly at random, a subset $Y$ of $X$, where $Y$ has size 5. Define the events

• A = "1 is an element of $Y$",
• B = "7 is an element of $Y$".

What is $\Pr(A|B)$?