write your answer as a simplified fraction.

Question

Two balls are to be selected without replacement from a bag containing 1 red, 1 blue,

1 green, 1 yellow, and 1 black ball. What is the probability that the red ball and then

the green ball is selected?

Answer 1

The bag has five balls, one of each color. So the probability of choosing the correct color on the first try is one out of five, or 1/5. Once that ball is selected, there are now four balls in the bag, so the probability of selecting the correct color on the second try is one out of four, or 1/4. This is a process where two independent events must both happen, so we use the AND rule of probability, meaning that we multiply the individual probabilities. So Since P1 = 1/5, and P2 = 1/4, multiply 1/5 x 1/4 = 1/20 is the probability of selecting the correct colored balls in that order. Keep in mind that this is based on a determined order of selection. If the balls could have been selected in either order (first or second) the probability would change.

Hope that helps