Topscore 2 - #33 Mistake?

[Member 8586]

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A father and mother have 3 boys in a row. What is the probability that the fourth child will be another boy?

They have the answer as 1:2, but shouldnt it be 1:1? Equal chance of having a boy as a girl? Or is it just how a ratio is the same as a fraction so 1:2 = 1/2 ?

 

[SnowyRox]

They have the answer as 1:2, but shouldnt it be 1:1? Equal chance of having a boy as a girl? Yes

Or is it just how a ratio is the same as a fraction so 1:2 = 1/2 ? No

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