A local gym offers its members the opportunity to choose between two fitness classes: yoga and dance. Of the $400$ gym members, $300$ regularly attend yoga, $80$ regularly attend dance, and $50$ regularly attend yoga *and* dance. Using this information, answer each of the following questions.
Let $Y$ be the event that a randomly selected gym member regularly attends yoga and $D$ be the event that a randomly selected gym member regularly attends dance.
**What is $P(Y)$, the probability that a gym member attends yoga?** [[☃ input-number 1]]
**What is $P(D)$, the probability that a gym member attends dance?** [[☃ input-number 2]]
**What is $P(Y\text{ and }D)$, the probability that a gym member attends yoga *and* dance?** [[☃ input-number 3]]
**What is $P(Y\text{ or }D)$, the probability that a gym member attends yoga *or* dance?** [[☃ input-number 4]]