# Math Help - Probility

1. ## Probility

A bag contains 3 orange, 3 red, and 2 black balls. Two balls are to be selected at random, and the first ball selected will be placed back in bag before second marble is selected. What is the probablility that both balls selected will be black? 1/8 or 1/16. I think 1/8 because it is a total of 8 balls. Am I correct?

2. ## Re: Probility

Originally Posted by tahirakw
A bag contains 3 orange, 3 red, and 2 black balls. Two balls are to be selected at random, and the first ball selected will be placed back in bag before second marble is selected. What is the probablility that both balls selected will be black? 1/8 or 1/16. I think 1/8 because it is a total of 8 balls. Am I correct?
Replacing the ball after it is drawn makes the events independent.
Therefore, multiply: $\left(\frac{2}{8}\right)^2$.

3. ## Re: Probility

Thanks. so that gives me 4/64 when I reduce its 1/16?