A bag contains 10 marbles. There are 5 green, 2 red, and 3 yellow. What is the probability of selecting a green marble?
We look at the number of options that satisfy a certain condition (such as the number of ways to draw a green marble) and divide by the number of ways we can draw a marble from the bag.
We have 5 green marbles and we'll divide by 10 marbles in the bag, so we have: