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At least 3 zeroes (
Posted on 20181003
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How many binary strings of length n, having three or more zeroes, exist?
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Submitted by
Ady TZIDON
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solution
 Comment 2 of 5 
Altogether there are 2^n binary strings of length n. There is 1 that has no zeros, n that have one zero and C(n,2)=n*(n1)/2 that have two zeros.
The answer is
2^n  1  n  n*(n1)/2
=
2^n  (n^2+n)/2  1
Posted by
Charlie
on 20181003 11:58:11
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