Answer:
30%
Explanation:
Though this question should be asked in the math category, I can assist you.
Our first step is finding the total amount of cars driving past her house in an hour. 10 + 8 + 42 = 60, so 60 is our total amount.
We want to find the probability that the car is <em>not</em> white, so lets figure out how many cars are not white. 10 blue + 8 red = 18 cars that aren't white. So 18 out of 60 cars that pass are not white.
= 0.3
To turn 0.3 into a percent we must know that 1.0 = 100%. 0.9 would be 90%, 0.85 would be 85%, etc. This means that 0.3 is 30%.
Hope that helped, remember to ask in the right category next time!