Question

An experiment has two possible outcomes A or B. The probability that A will occur is. You are going to perform this experiment eight times. What is the probability that B will occur at least three times?

Answer 1

An experiment has two possible outcomes A or B. The probability that A will occur is 1/3. You are going to perform this experiment eight times. What is the probability that B will occur at least three times?

Answer 2

this is a binomial relationship

(A + B)^8 ... (1/3 + 2/3)^8

three times means ... NOT 0, 1, or 2

p(B ≥ 3) = 1 - {[(1/3)^8 + [8 * (1/3)^7 * (2/3)] + [28 * (1/3)^6 * (2/3)^2]}