A couple has six girls in succession At that point what is t

A couple has six girls in succession. At that point, what is the probability that their seventh child will be a girl?

What is the probability that a couple will have 7 girls in a row?

Solution

The probability of having a girl first is 50%. For having it the next time as well is 50% * 50% = 25%. For that exact order of 6 girls and then 1 boys would then be 0.5^7 = 0.0078125, meaning:

0.78125% of a chance.
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The probability of having a girl first is 50%. For having it the next time as well is 50% * 50% = 25%. For that exact order of 7 girls in a row = 0.5^7 = 0.0078125

If it doesn\'t matter which group of sex is first (doesn\'t matter if first girls and then boys, or first boys and then girls) then you can remove one of the multiplications of 50%, giving 0.5^7 = 0.0078125, giving:

0.78125 % of a chance.