Question

In a lottery game, a single ball is drawn at random from a container that contains 25 identical balls numbered from 1 through 25. Use the equation P(AUB)=P(A) + P(B) - P(ANB), where A and B are any events, to compute the probability that the number drawn is prime or greater than 12.
The probability that the number drawn is prime or greater than 12 is : ___________

Answer 1

Answer:

17/25

Step-by-step explanation:

The equation for the probability of two events that are not mutually exclusive is:

p(A ∨ B) = p(A) + p(B) - p(A ∧ B)

A = the number is prime

B = the number is prime

The numbers are:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25

Here are the 8 prime numbers that satisfy event A:

3, 5, 7, 11, 13, 17, 19, 23

p(A) = 8/25

Here are the 13 numbers that are greater than 12 that satisfy event B:

13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25

p(B) = 13/25

Here are the 4 numbers that satisfy both event A and event B:

13, 17, 19, 23

p(A ∧ B) = 4/25

p(A ∨ B) = p(A) + p(B) - p(A ∧ B)

p(A ∨ B) = 8/25 + 13/25 - 4/25

p(A ∨ B) = 17/25