At Bob's Auto Plaza there are currently 15 new cars, 4 used cars, and 4 new trucks. But, there are no used trucks. Bob is going to choose one of these vehicles
at random to be the Deal of the Month. What is the probability that the vehicle that Bob chooses is used or is a truck?
Do not round intermediate computations, and round your answer to the nearest hundredth.
(If necessary, consult a list of formulas.)