The shelf life (in years) of a laser pointer battery is a continuous random variable with probability density function
(A) Find the probability that a randomly selected laser pointer battery has a shelf life of 3 years or less.
(B) Find the probability that a randomly selected laser pointer battery has a shelf life of from 3 to 9 years.
(C) Graph y=f(x) for [0, 10] and show the shaded region for part (A).