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Starting the Scrabble Game (Posted on 2018-01-24) Difficulty: 2 of 5
To determine who plays first in a game of Scrabble, each player draws a tile and the one closest to A wins, except if one draws a blank tile. A blank tile beats any letter.

If there are only two players, what is the probability they both draw the same letter or both draw a blank?

The letters (and counts) are E (12); A, I (9); O (8); N, R, T (6); D, L, S, U (4); G (3); B, C, F, H, M, P, V, W, Y (2); J, K, Q, X, Z (1); and 2 blanks. -- 100 tiles in all.

Bonus: What if there are more than two players: what is the probability of a tie for who plays first? (subsequent play is to the left so 2nd, etc. player are not determined by the draw).

See The Solution Submitted by Charlie    
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Solution No Subject | Comment 1 of 8
For a letter that occurs n times, the probability that both draw it is n/100*(n-1)/99.  Each letter is independent so we can just add them up:
(12*11+9*8*2+8*7+6*5*3+4*3*4+3*2+2*1*10+1*0*5)/(100*99)
=496/9900=.05010101

The bonus is pretty complicated.  I'll need to save it for later.

Edit to fix errors.  I made an impressive 3 total.  
Forget to consider the blank.  (9 changed to 10)
Had a + that should have been * (2*1+9, now 2*1*10)
Wrong denominator.  Draws without replacement (10000 changed to 100*99)

Edited on January 25, 2018, 3:07 pm


Edited on January 26, 2018, 9:40 am
  Posted by Jer on 2018-01-24 14:47:34

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