Suppose we have a bag with $60$ balls of the same size. Their colors are red, black and white. To pick a red ball with absolute certainty, we have to pick at least $36$ balls. For a black one, we have to pick at least $40$. How many white balls are there in the bag?
I am not sure what the task means by 'absolute certainty'. How could I count the total number of white balls since we are talking about probabilities here?