You have 11 chocolate chip cookies left, 18 macadamia nut left, and 27 oatmeal raisin cookies left. Your brother steals some. What is the smallest number of cookies your brother must take in order to be 100% certain he gets an oatmeal raisin cookie?
This problem has been confusing me for ages if someone could give me an answer and how they got the answer that would be a great help!
11+18 = 29 that are not oatmeal
so 30 cookies will guarantee an oatmeal
To determine the smallest number of cookies your brother must take in order to be 100% certain he gets an oatmeal raisin cookie, we need to find the scenario where all the chocolate chip and macadamia nut cookies are gone, and only the oatmeal raisin cookies remain.
First, let's find the total number of cookies you have:
11 (chocolate chip) + 18 (macadamia nut) + 27 (oatmeal raisin) = 56 (total cookies)
Now, let's consider the worst-case scenario, where your brother wants to make sure he gets an oatmeal raisin cookie. In this case, he would need to take all the other types of cookies, leaving only oatmeal raisin cookies behind.
Taking all the chocolate chip and macadamia nut cookies:
11 (chocolate chip) + 18 (macadamia nut) = 29 cookies
Now, subtracting the number of cookies your brother needs to take from the total number of cookies you have will give us the answer:
56 (total cookies) - 29 (chocolate chip and macadamia nut cookies) = 27
Therefore, your brother must take a minimum of 27 cookies to be 100% certain he gets an oatmeal raisin cookie.
In summary, the answer to how many cookies your brother must take is 27, and the way to arrive at this answer is to ensure that he takes all the other types of cookies, leaving only the oatmeal raisin cookies.