Give a rigorous mathematical proof of:
\[ A \cup (B \cap A^c)=A \cup B\]
Give a mathematically correct proof of Booleโs inequality
A box contains 20 blue balls and 10 green balls. Define appropriate sample spaces and events and use them to find
the probability to select a blue ball from the box.
the probability to select (in one move) a blue ball and a green ball.