One marble drawn from a bag with 3 red, 2 blue, and 5 green marbles. What is the probability the marble is red?

One marble drawn from a bag with 3 red, 2 blue, and 5 green marbles. What is the probability the marble is red?

• A. 1/2
• B. 1/4
• C. 3/10
• D. 3/5

Answer: (C)

Probability is the ratio of favorable outcomes to all possible outcomes. Here, the event is drawing a red marble. There are 3 red marbles out of a total of 10 marbles (3 red + 2 blue + 5 green). So the chance of red is 3 out of 10, written as 3/10, which is 0.3 or 30%. The other fractions would imply more or fewer red marbles than exist in the bag (for example, 1/2 would mean 5 red out of 10; 1/4 would suggest 2.5 red, which isn’t possible; 3/5 would require 6 red), so they don’t fit the bag’s composition.

Probability is the ratio of favorable outcomes to all possible outcomes. Here, the event is drawing a red marble. There are 3 red marbles out of a total of 10 marbles (3 red + 2 blue + 5 green). So the chance of red is 3 out of 10, written as 3/10, which is 0.3 or 30%. The other fractions would imply more or fewer red marbles than exist in the bag (for example, 1/2 would mean 5 red out of 10; 1/4 would suggest 2.5 red, which isn’t possible; 3/5 would require 6 red), so they don’t fit the bag’s composition.