SOLUTION: Out of seven random numbers what are the odds of finding numbers that add up to eighteen? How is this calculated?

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Question 390516: Out of seven random numbers what are the odds of finding numbers that add up to eighteen? How is this calculated?
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
I will assume a random number to be any number from 0,1,2,3,4,5,6,7,8,9.
That said, the number of ways of getting seven random numbers that add up to 18 is 24C6+=+24%21%2F%286%2118%21%29+=+134596. The total number of 7 digit random numbers, assuming repetition, is 10%5E7.
Therefore the odds of finding numbers that add up to eighteen is 134,596/(10,000,000 - 134,596), or 134,596:9,865,404.