(b) 20% of the cars produced by a manufacturer are found to be defective. A sales representative received a shipment of 8 randomly selected cars from the manufacturer. (i) What is the probability that one car is defective? (ii) What is the probability that at least two cars are defective? (iii) Calculate the expected number of defective cars in this shipment and its variance. The life of a mobile phone battery \"Always Ready\" is normally distributed with a mean of 18,000 hours and a standard deviation of 2,000 hours. (i) What percentage of the batteries will last between 15,000 hours and 23,000 hours? (ii) What percentage of the batteries will last at most 13,000 hours? (iii) What percentage of the batteries will last at least 30,000 hours? (iv) At most, how many hours will 85% of the batteries last