Suppose that the value of a stock varies each day from \($16\) to \($25\) with a uniform distribution.

a. Find the probability that the value of the stock is more than \($19.

b.\) Find the probability that the value of the stock is between \($19\) and \($22.

c.\) Given that the stock is greater than \($18,\) find the probability that the stock is more than \($21.\)