Suppose we know that the length of time it takes

Suppose we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute.

a) What is the probability that a randomly selected college student will find a parking spot in the library parking lot in less than 2.5 minutes?

b) What is the probability that a randomly selected college student will take between 2.5 and 4.5 minutes to find a parking spot in the library parking lot?

c) What is the point in the distribution in which 95.44% of the college students exceed when trying to find a parking spot in the library parking lot? What about 99.7%? (Explain/show how you obtain your answer.)