SOLUTION: A pair of dice is rolled 20 times and the sum is recorded. Find the probability of rolling at least 2 double sixes.

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Question 981931: A pair of dice is rolled 20 times and the sum is recorded. Find the probability of rolling at least 2 double sixes.
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
There are 36 possible rolls and only one is a double 6, so the
probability of one double 6 in 1 roll is 1/36.

on your TI-84 

press 2ND VARS

Scroll down to binomcdf(, press ENTER

         trials:20
         p:1/36
         x value:1
         Paste 

Press ENTER

binomcdf(20,1/36,1)

Press ENTER

See .8945518471

That's the probability of getting either no double 6's or just
1 double 6.  So we must subtract that from 1. So 

Press 1, -, 2ND (-)  

See 1-Ans

Press ENTER

.1054481529

Edwin