The probability that Stephen randomly selects a sugar cookie from the bag and eats it, then randomly selects a peanut butter cookie is 3/58 (or) 0.052
Explanation:
The bag of cookies contain 9 chocolate chip cookies, 7 peanut butter
cookies, 6 sugar cookies and 7 oatmeal cookies.
Therefore, the total number of cookies in the bag = 9+7+6+7 = 29 cookies.
It is given that, Stephen randomly selects a sugar cookie from the bag and eats it.
The probability to select a sugar cookie = No.of sugar cookies / total
⇒ 6/29
After that, he randomly selects a peanut butter cookie. We know that the bag now contains 1 cookie less than the total cookies because Stephen ate one sugar cookie.
Therefore, the total number of cookies in the bag = 28 cookies.
Probability to select a peanut butter cookie = No.of peanut cookies / total
⇒ 7/28
⇒ 1/4
The total probability = P(sugar cookie) × P(peanut cookie)
⇒ (6/29) × (1/4)
⇒ 6/116
⇒ 3/58 (or) 0.052