A maintenance firm has gathered the following infor- mation regarding the failure mechanisms for air conditioning system evidence of gas leaks evidence of electrical failure yes no yes 55 17 32 31 The units without evidence of gas leaks or electrical failure showed other types of failure. If this is a representative sample of AC failure, find the probability

(a) That failure involves a gas leak

(b) That there is evidence of electrical failure given that there was a gas leak

(c) That there is evidence of a gas leak given that there is evidence of electrical failure