Ther is a questioner sent out, the return rate is 47%. Approximetly 77% of the population is urban: but returing this questionaire is not dependant on whether you are and urban dweller.

a. determine the probability that the person randomly chosen from the sample is urban dweller and returnes the questionair.

b. determine the probability that the person from the sample is a rural dweller and does not return the questionair.