Bella keeps a supply of red, blue, and black pens in a drawer. The drawer has 13 red pens, 18 blue pens, and 8 black pens. If Bella wants a red pen, what is the minimum number of pens she has to pull out from the drawer to make sure she gets a red pen?
27
To find the minimum number of pens Bella has to pull out to make sure she gets a red pen, we need to consider the worst-case scenario. The worst-case scenario would be if all the pens that Bella initially pulls out are either blue or black.
In this case, Bella would have to pull out all the blue pens (18) and all the black pens (8) before reaching the red pens. So, she would have to pull out 18 + 8 = 26 pens in total to make sure she gets a red pen.
Therefore, the minimum number of pens Bella has to pull out from the drawer to make sure she gets a red pen is 26.