Dan's Diner employs three dishwashers. Al washes 40% of the dishes and breaks only 1 % of

Question:

Dan's Diner employs three dishwashers. Al washes 40% of the dishes and breaks only 1 % of those he handles. Betty and Chuck each wash 30% of the dishes, and Betty breaks only 1 % of hers, but Chuck breaks 3% of the dishes he washes. (He, of course, will need a new job soon....) You go to Dan's for supper one night and hear a dish break at the sink. What's the probability that Chuck is on the job?