Posted by Dan on Tuesday, May 21, 2013 at 1:37am.
The size of the sample space of the last throw is 20*20=400.
Out of the 400 outcomes, Bret needs those where his throw is 11 or more than Shawn's, namely:
(12,1),(13,1),(14,1)...(20,1)
(13,2),(14,2)...(20,2)
...
(19,8),(20,8)
(20,9)
There are ∑(i), i=1,9 outcomes.
Can you figure out the probability, and a+b?
Please tell the answer. I'm not able to get it.
Thanks.
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