A bag contains 2 red, 2 blue, and 2 green marbles, Sue takes one marble at a time from this bag without looking. What is the least number of marbles Sue must take from this bag to be sure that she has taken 2 marbles of the same color?

A) 2 B)3 C)4 D)6

Lol, 4

To find the least number of marbles Sue must take from the bag to be sure that she has taken 2 marbles of the same color, we need to consider the worst-case scenario. In this scenario, she picks marbles of different colors every time until she has taken one of each color.

Initially, she can choose any color marble. Let's say she picks a red marble.

Now, Sue needs to pick another marble that is a different color from the red marble. She can pick either a blue or a green marble, resulting in 2 possibilities.

If Sue picks a blue marble, she will have one red and one blue marble. In this case, the next marble she picks will ensure that she has two marbles of the same color. If she picks a red marble, she will have two red marbles, and if she picks a blue marble, she will have two blue marbles.

If Sue initially picks a green marble, the same logic applies. She will have one red and one green marble, and the next marble she picks will result in having two marbles of the same color.

Therefore, in the worst-case scenario, Sue needs to pick at least 3 marbles to be sure that she has taken 2 marbles of the same color.

Thus, the answer is B) 3.