There are four parcels namely A, B, C and D in a room. A particular I-phone is in one of them. The probability that it is in parcel A is $\frac{2}{5},$ but if it is not in parcel A its probability is equally likely to be either in B or C or D.  I sent any delivery man to bring one of a parcel to me. The Probability that my delivery man brings the parcel A is  $\frac{2}{3}$ and the probability that he brings any other parcel is $\frac{1}{3}.$ Let $\alpha =I$ get the particular I-phone, $\beta =$ my delivery man brings parcel A