Question

A bag contains 4 blue marbles, 6 red marbles, 3 yellow marbles, and 5 black marbles. What is the probability that you choose two marbles, without replacement, that are both black? Answer as a decimal to the nearest thousandths place (3 after the decimal).

Answer 1

.065

Explanation:

The total number of marbles is

4 blue marbles+ 6 red marbles+ 3 yellow marbles+5 black marbles=18

P(1st black) = Black/total = 5/18

You keep the marble

The total number of marbles is

4 blue marbles+ 6 red marbles+ 3 yellow marbles+4 black marbles=17

P(2st black) = Black/total = 4/17

Multiply the probabilities together

P(black,black)= 5/18 * 4/17 =10/153=.065359477 =.065