Tires salvaged from a train wreck are on sale at the Getrich Tire Company. Of the 15 tires offered in the sale, 5 have suffered internal damage and the remaining 10 are damage free. You randomly selected and purchased two of these tires.
a. What is the probability that the tires you purchased are both damage free?
b. What is the probability that exactly one of the tires you purchased is damage free?
c. What is the probability that at least one of the tires you purchased is damage free?