In a closed box, 18 red balls, 17 green and 16 white balls were placed.

In a closed box, 18 red balls, 17 green and 16 white balls were placed. What is the smallest number of balls you need to pull out so that the red ball is in the middle of them?

To be sure to pull out the red ball, you must leave only red balls in the box. To do this, remove all the balls that are not red. And this is 17 + 16 = 33 balls. Thus, the 34 ball will definitely be red. That is, the smallest number of balls that need to be pulled out is 34.