In a Local Cellular Phone Area, Company a Accounts for 60

Multiple Choice

In a local cellular phone area, company A accounts for 60% of the cellular phone market, while company B accounts for the remaining 40% of the market. Of the cellular calls made with company
A, 1% of the calls will have some sort of interference, while 2% of the cellular calls with company B
Will have interference. If a cellular call is selected at random and has interference, what is the
Probability that it was with company A?

A) 0.071
B) 0.429
C) 0.571
D) It cannot be determined.