The life spans of trucks manufactured by company A are normally distributed with a mean of 10 years and variance of 25 years. a) What is the probability that a random truck bought from company A will have a life span of more than 12 years? b) What is the probability that a random truck bought from company A will have a life span of less than 7 years? c) What is the probability that a truck randomly bought from company A will have a life span of more than 5 years but less than 25 years