You only need to consider the situations where 10 or 11 of the babies are girls, then subtract those probabilities from 1. This will give probability that any other number up to 9 of the babies are girls.
Use binomial theorem.

n = 11
k = 10,11
p = 1/2
I'm not sure if this is right but you can set up an equation and solve to find Maggie's age:
Maggie's brother's age = b
Maggie's age = m
b = 12 - 3m
44 = 12-3m
12-3m = 44
-12 -12
-3m = 32
÷ 3 ÷3
m = 10.67
So this would be Maggie's age
I hope this helped :)
<span>p=210e^(0.0069*20)
'e' is a mathematical constant equal to 2.718281828459
</span>
<span>0.0069*20 = .138
e^.138 =
</span>
<span>2.718281828459^.138 =
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1.1479755503
</span>
</span>
</span>
210 * <span>1.1479755503 =
</span>
<span>
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<span>
241.074865563
</span>
</span>
</span>