Assist with these 6 HW stat questions

The mean time it takes for a particular make/model of a phone to break down and require repair services from the manufacturer is 30 months, with a standard deviation of 16 months. The manufacturer's warranty for the phone is 1 year (12 months). Assume normal distribution.

1. What is the probability that the phone will break down within the warranty period and the manufacturer must cover the cost of repair?

1. What is the probability the phone will function for at most 25 months?

The HR department of a local company administers a litmus test to applicants. The mean score on the test is 245 with a standard deviation equal to 35 points. Assume normal distribution.

1. What is the probability that an applicant scores between 230 and 280 points?

1. The manager wants to consider only those applicants who have scored in the top 5%. What score marks that cut-off point?

The time between failures for an industrial machine is exponentially distributed with a mean of 40 days.

1. What is the probability that a failure occurs in the next 30 days?

1. In a medical study it was found that in a specific group 35% of individuals smoked, in that same group it was found that 5% smoked and had a heart condition. What is probability that an individual in this group had a heart condition given the individual smoked?