TWO COMPUTERS A AND B TO BE MARKETED . A SALESMAN WHO IS ASSINED THE JOB TO FIND CUSTOMERS FOR THEM HAS 60% AND 40% CHANCES RESPECTIVELY OF SUCCEEDING IN CASE OF COMPUTER IN CASE OF COMPUTER A AND B.THE COMPUTERS CAN BE SOLD INDEPENDENTLY .GIVEN THAT HE WAS ABLE TO SELL AT LEAST ONE COMPUTER ,WHAT IS THE PROBABILITY THAT COMPUTER A HAS BEEN SOLD?