Question

Adding probability:
There are 600 students in a high school junior class. Of these 600 students, 350 regularly wear a watch to school, 325 regularly wear earrings, and 300 regularly wear a watch and earrings. Using this information, answer each of the following questions.

Let W be the event that a randomly selected junior regularly wears a watch and E be the event that a randomly selected junior regularly wears earrings.

1) What is P(W) the probability that a junior wears a watch?
2)What is P(E) the probability that a junior wears earrings?
3)What is P(W and E) the probability that a junior wears a watch and earrings?
4)What is P(W or E) the probability that a junior wears a watch or earrings?

Answer 1

Answer:

1) P(W) = 350/600 = 7/12

2) P(E) = 325/600 = 13/24

3) P(W&E) = 300/600 = 1/2

4) P(W U E) = (350+325-300)/600

= 375/600 = 5/8