What is the probability

Question

What is the probability

A copy center has two copyphotos. The likelihood that the machines will require service for a random week is, after long experience, estimated P(A) = 0.040 for one and P(B) = 0.025 for the other and P(A ∩ B) = 0.003 for both machines.

a) Calculate the probability that at least one of the machines will need service in a random week.

b) Calculate the probability that none of the machines will need service in a random week.

Answer 1

Hello Nasir O.,

Part a is asking for P(A ∪ B). The formula is P(A ∪ B) = P(A) + P(B) – P(A ∩ B).

See if you can substitute in the formula and get the answer to part a.

Part b is the exact opposite (complement) of part a. So if you know the probability of at least 1, you can subtract it from 100% or 1 to get the probability of none in part b.

You may send in your answers to be checked by an expert if you like.