Question

Suppose that an urn contains 3 black marbles, 7 yellow marbles, and 10 green marbles. If one marble is selected, determine the probability that it is green. The answer should be an integer or a simplified fraction.

Answer 1

1/2

Explanation:

Simple probability is a ratio of the number of ways the thing we want to happen can to the total possible outcomes.

(For example, we flip a coin and want heads, but it can land on heads or tails. Our probability of getting heads is 1/2, one way to get heads over the 2 possible outcomes)

So for this problem, there's 20 possible things that CAN happen (3 + 7 + 10) and 10 ways we get what we want (a green marble).

Our probability of getting a green marble is
`(10)/(20\\)`, which simplifies to
`(1)/(2)`