Question

On any given day, the probability that Angelo will buy lunch is .40 and the probability that Ben will buy lunch is .35. If the probability that both boys will buy lunch is .15, what is the probability that Angelo or Ben will buy lunch on a given day?

A) 0.60
B) 0.50
C) 0.75
D) 0.80.

Answer 1

The probability that either Angelo or Ben will buy lunch on a given day is 0.60, calculated using the formula P(A OR B) = P(A) + P(B) - P(A AND B).

Step-by-step explanation:

The problem is asking for the probability that Angelo or Ben will buy lunch on a given day, which can be calculated using the formula for the probability of the union of two events: P(A OR B) = P(A) + P(B) − P(A AND B). Here, P(A) is the probability that Angelo will buy lunch, P(B) is the probability that Ben will buy lunch, and P(A AND B) is the probability that both will buy lunch. Substituting the given probabilities into the formula gives us:

P(A OR B) = 0.40 + 0.35 − 0.15 = 0.60.

Therefore, the probability that either Angelo or Ben will buy lunch on a given day is 0.60, which corresponds to answer choice A.