The probability of a telesales representative making a sale on a customer call is 0.15, find the probability that

Question 1 The probability of a telesales representative making a sale on a customer call is 0.15, find the probability that 1.1) no sales are made in 10 calls =(5 marks) 1.2) more than 3 sales are made in 20 calls =(5 marks) Representatives are required to achieve a mean of at least 5 sales each day 1.3) find the least number of calls each day a representative should make to achieve this requirement :5 marks) 1.4) calculate the least number of calls that need to be made by a representative for the probability of at least 1 sale to exceed 0.95