Probability question for college Sorry to post this really simple question about probability here but my hands are forced here.My little brother came home with a question which I needed to help him solve. The only problem here is that I started been confused myself.
here is the problem statement. there are 4 players of marbles, and 20 marbles in total. the rule of the game is that he who manage to get the absolute maximum of marbles is the winner(absolute in the sense that no other player should have the same number of marbles).
Question 1 what is the minimum number of marbles should one player have to be assured of the victory.  
Question 2 what is the probability that the player with that number of marbles will win
so to me the question 1 is kind of logical and common sense.one player should have at least 11 marbles to be assured. So I got that because it's kind of obvious to me but I don't know how to explain to my brother how I end up with that number 11.  
the second question is completely confusing for me.I know it's not permutation because there is not order of any arrangement here. it's not just a combination.
I really need help here. Thanks for reading this
EDIT i think i didn't understand the topic very well, the question 2 was really about the probability of any of them been assured of winning. That as well i feel like it's 1/4 but just in case i would like to cross check with you.Thanks for those who quickly responded
 A: If you have $10$ marbles or fewer, it’s possible that another player has all the rest, in which case you have not won: that player has at least as many as you have. If you have $11$, however, there are only $9$ other marbles, so even if one player has all of them, you win.
If you have $11$ marbles, you are certain to win, so your probability of winning is $1$.
A: 
(1) You are correct: The minimum number of marbles to be ASSURED of the victory = $11$ marbles.



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*Then the total number of marbles that the other three players can have is $20 - 11 = 9$. No matter how to split up $9$ among three players, even if one player has all the other 9 marbles,  $11 > 9$, ($11 > 20/10 = 10$). So a player with 11 marbles is guaranteed to win...



(2) So the probability that the player with $11$ marbles who is ASSURED of victory will win = $1$ 



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*After all, the rules of the game are "he who manage to get the absolute maximum of marbles is the winner" (that means WIll certainly win, not might win.)



