Question

The number of marbles of different colors stored in a hat is listed below:

Answer 1

4 red marbles
10 green marbles
7 blue marbles
4+10+7=21 marbles total

P(blue)=(blue marbles)/(total marbles)=7/21=1/3

P(blue,blue)=(blue marbles)/(total marbles)*(blue marbles)/(total marbles)=7/21*7/21=1/3*1/3=1/9

Note:Because the marble is replaces, we can keep '21' as the number of total marbles for the second draw

Answer=1/9

Answer 2

The probability is 7/21 * 7/21, or 0.0159.