A town has two malls. 62% of the town’s residents shop at Willow Creek Mall. 73% of the residents shop at Two Harbors Mall. 48% of the residents visit both malls. On any given day, what is the probability that a person chosen at random will visit either Willow Creek or Two Harbors? A. 0.87 B. 0.64 C. 0.62 D. 0.75 E. 0.48

Question

A town has two malls. 62% of the town’s residents shop at Willow Creek Mall. 73% of the residents shop at Two Harbors Mall. 48% of the residents visit both malls. On any given day, what is the probability that a person chosen at random will visit either Willow Creek or Two Harbors? A. 0.87  B. 0.64 C. 0.62 D. 0.75 E. 0.48

mathmale · Answer

There's an Addition Rule for probability.  Mind looking that up in your notes?

Supposing that A and B are independent events that can still happen together.  Let A=P(resident visits WC Mall; let B=P(resident visits TH Mall.

We are given:  P(A)=0.62, P(B)=0.73, and P(A AND B)=0.48.

What does the Addition Formula tell us to do in order to find P(A OR B)?