probability questions

c) An insurance company classifies drivers as low-risk, medium-risk and high-risk. Of those insured, 60% are low-risk, 30% are medium-risk and 10% are high-risk. After a study, the company finds that during a year period, 1% of the low-risk drivers had an accident, 5% of the medium-risk drivers had an accident and 9% of the high-risk drivers had an accident. Draw a tree diagram to illustrate the above situation. (3 marks) ii) Find the probability that the drivers did not have an accident. (2 marks) iii) Given that the drivers had an accident, what is the probability that they insured are medium-risk