Sir, I am stuck on this question

In a marketing firm, 60% of all trainees have participated a training session on selling a new product. Based on the existing record. 70% ofthose who have participated the training session will end up selling the new product. whereas 30% of those who have not participated the training session will end up selling the new product. (a) What is the probability that a randomly chosen trainee will end up selling the product? (b) For a randomly chosen trainee who has not sold the new product. what is the probability that helshe has participated the training session? is) Consider now that 50 independent trainees are randomly chosen. Answer the following questions. (i) What is the probability that exactly 20 of them will end up selling the new product? (ii) What is the expected number of trainees who will end up selling the new product