5. In a taxi company, there are currently 60 free cars: 10 black, 20 yellow, and 30 green. At a call, one of the cars, which happened to be the closest to the customer, drove out. Find the probability that a non-green taxi will arrive.
Solution. The probability that a car of a certain color will arrive is calculated as the ratio of the number of favorable outcomes (the arrival of a car of the desired color) to the total number of outcomes (the total number of cars). Thus, the probability of a green car arriving is $\frac{30}{60}=\frac{1}{2}$.