Answer:
1. P(N) = 3/5
2. P(R) = 2/5
3. P(N and R) = 1/4
4. P(N or R) = 3/4
Step-by-step explanation:
1. Let's review the information given to us to answer the problem correctly:
Number of students in a high school senior class = 500
Number of students that regularly wear a necklace = 300
Number of students that regularly wear a ring = 200
Number of students that wear a necklace and a ring = 125
2. What is P(N), the probability that a senior wears a necklace?
Let's recall the formula of probability:
Probability = Number of favorable outcomes/Total of possible outcomes
Substituting with the real given values:
P(N) = 300/500 = 3/5 (Dividing by 100 numerator and denominator)
P(N) = 3/5
3. What is P(R), the probability that a senior wears a ring?
Substituting with the real given values:
P(R) = 200/500 = 2/5 (Dividing by 100 numerator and denominator)
P(R) = 2/5
4. What is P(N and R), the probability that a senior wears a necklace and a ring?
Substituting with the real given values:
P(N and R) = 125/500 = 1/4 (Dividing by 125 numerator and denominator)
P(N and R) = 1/4
5. What is P(N or R), the probability that a senior wears a necklace or a ring?
P(N or R) = P(N) + P(R) - P(N and R)
Substituting with the real given values:
P(N or R) = 3/5 + 2/5 - 1/4
P(N or R) = 5/5 - 1/4
P(N or R) = 1 - 1/4
P(N or R) = 3/4
