ANSWER
0.0593
EXPLANATION
The total number of cookies in the bag is,
[tex]5+6+6+6=23[/tex]When Warren takes the first cookie, the probability of it being a peanut butter cookie is 6 out of 23,
[tex]P(pb_1)=\frac{6}{23}[/tex]If the first cookie was peanut butter, when he takes the second cookie there are only 5 peanut butter cookies left and a total of 22 cookies, so the probability of that second cookie being peanut butter is,
[tex]P(pb_2)=\frac{5}{22}[/tex]So, the probability that Warren selects 2 peanut butter cookies from the bag is,
[tex]P(2pb)=\frac{6}{23}\times\frac{5}{22}\approx0.0593[/tex]Hence, the probability that he takes 2 peanut butter cookies is 0.0593.