How many white balls are there in the box most probably? There are n balls in a box. Some of them are white. A ball drawn from the box turns out to be white. How many white balls are there in the box most probably?
Alright, well i know there are originally n white balls and if I'm grabbing a white ball then there will now be n-1 balls left. 
P(grabbing a white ball)= I'm not sure at all, for all we know that was the only white ball. Or there could be 100 balls and 99 are white. I really don't know how to approach this. I feel like we are given very minimal information. If someone could provide me with a solution that would be awesome! Thanks guys! :)
 A: The question is a bit strange, admittedly. This is how I would interpret it (SEE COMMENTS): Given the knowledge that there is at least one white ball in the box, and that the probability of selecting any ball is equal, then what is the number of white balls that will maximize the chance that a randomly pulled ball is white?
In this case, the answer is of course $n$.
There is another, perhaps more sensible option. We could also consider that the box was at one point filled, presumably by another person who did not care how many balls were white. Maybe she chose from a large box that had white and blue balls in equal proportion. In that case $n$ white balls would make it very likely that you get a white ball, but this is not very likely to happen.
Of course, there is no reason why there should be equal probability of white and blue, or even that there should be only two choices. Perhaps an even more sensible answer is $1$, because there is a staggering array of possible choices for balls to put in the box, and most of them would result in one white marble (well, most of them would result in none, actually, but we know there's at least one).
Pick your poison, really, because I would bet money that this problem was chosen to make a point: incomplete information is not an excuse to throw up your hands and say "It can't be done!" Rather, it's a time to choose some reasonable assumptions, state them carefully, and derive results from them rigorously.
A: A white ball is most likely to be chosen if the all the balls in the box are white. I'm not sure if this answers the question though.
