An insurance company classifies its customers into three groups,a,b and c. Groups a accounts for 20% of the total custermers, groupe b accounts 40%, and accounts for 40%. For people in groupe a,b and c, the probabilities of having an accident in one year are 0,0.1,and 0.2 respectively . For any customer, the probability of having more than one accident in one year is zero. (a) a customer is chosen at tandem. Given this customer is from groupe c.