Black car probability

Oskar observes the arrivals and departures of cars in the parking lot. At one point, there were 99 cars in the parking lot: 25 red, 17 white, and the rest were black. What is the percentage probability that a black car was leaving the parking lot at a given time?

Final Answer:

p =  57.58 %

Step-by-step explanation:

$$\begin{gathered} n=99 \\ r=25 \\ w=17 \\ b=n-r-w=99-25-17=57 \\ p=100\cdot \frac{b}{n}=100\cdot \frac{57}{99}=\frac{100\cdot 57}{99}=\frac{5700}{99}=\frac{1900}{33}\%=57.58\% \end{gathered}$$

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