$300$ students in a high school freshman class are surveyed about what kinds of pets they have. Of the $300$ students, $200$ have a dog, $180$ have a cat, and $150$ have a cat *and* a dog. Using this information, answer each of the following questions.
Let $D$ be the event that a randomly selected student has a dog and $C$ be the event that a randomly selected student has a cat.
**What is $P(D)$, the probability that a student in the class has a dog?** [[☃ input-number 1]]
**What is $P(C)$, the probability that a student in the class has a cat?** [[☃ input-number 2]]
**What is $P(D\text{ and }C)$, the probability that a student in the class has a dog *and* a cat?** [[☃ input-number 3]]
**What is $P(D\text{ or }C)$, the probability that a student in the class has a dog *or* a cat?** [[☃ input-number 4]]