Two Switches

[charlie33]

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?

[danimmm]

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