An insurance company divides its customers into three classes R1, R2 and R3: good risks, average risks, and bad risks. The numbers of these three classes represent 20% of the total population for class R1, 50% for class R2, and 30% for class R3. Statistics indicate that the probabilities of having an accident during the year for a person in one of these three classes are 0.05, 0.15 and 0.30 respectively. 5 new clients who belong to the bad risk class were taken at random. The probability that none of them has an accident during the year is: