In Bill the Boring's dryer there are 11 black shirts, 8 gray shirts, 12 black sweaters, and 10 gray sweaters. Bill is going to take one of these pieces of clothing
out of the dryer at random to check if his clothes are completely dry. What is the probability that the piece of clothing Bill takes out is gray or is a shirt?
Do not round intermediate computations, and round your answer to the nearest hundredth.
(If necessary, consult a list of formulas.)