A bag contains 3 red, 2 blue, and 5 green balls. If you draw one ball, what is the probability it is blue?

• A. 1/3
• B. 1/5
• C. 2/5
• D. 1/2

Answer: (B)

Probability is found by comparing how many favorable outcomes there are to how many total outcomes are possible, assuming every ball is equally likely to be drawn. There are 3 red, 2 blue, and 5 green balls, so total balls = 10. The favorable outcomes (drawing blue) = 2. So the probability is 2/10, which simplifies to 1/5. That means the chance of drawing a blue ball is 1/5 (0.2). The other fractions don’t match the actual counts: 1/3 would need 3 blue out of 9, 2/5 would need 4 blue out of 10, and 1/2 would need 5 blue out of 10.