Brainteasers

Flashlight

Probability

Suppose we have a flashlight that has a compartment for two batter- ies. Let Ai denote the event that the ith battery fails. Assume we have P(A1) = 0.1 and P(A2) = 0.2. Calculate the probability that the flashlight works in case i) it needs both batteries to function, ii) it needs at least one battery to function.