To solve this problem, you need to understand the concept of probability and how it is calculated.
Probability is the likelihood of an event occurring. It is calculated by dividing the number of favorable outcomes by the total number of possible outcomes.
In this case, Gwen has a total of 4 blue pens, 8 black pens, 2 green pens, and 3 red pens in her drawer. She takes out two pens without replacing the first one.
To find the probability of Gwen pulling out a green pen first and then a blue pen, we need to calculate the number of favorable outcomes and the total number of possible outcomes.
The number of favorable outcomes is the number of green pens multiplied by the number of blue pens remaining after taking out the green pen. So, the favorable outcomes are 2 green pens and 4 blue pens.
The total number of possible outcomes is the total number of pens remaining after taking out the first pen. So, the total number of possible outcomes is the total number of pens (17) minus 1 (because the first pen was already taken out).
Therefore, the probability of Gwen pulling out a green pen first and then a blue pen is:
(2/17) * (4/16) = 1/34
So, the probability of Gwen pulling out a green pen first and then a blue pen is 1/34.