It is given that the probability that switch A is closed is 0.35 and the probability that switch B is closed is 0.40. It is also known that the 2 switches function independently. What is the probability that the radio is playing?
You didn't wrote how many switches are needed for the radio to work.
if both should be open than :
1. ask yourself what is the probability switch A is on: 1-0.35=0.65
2. ask yourself what is the probability switch B is on: 1-0.40=0.60
3. because both work independently 0.65*0.6=0.39
