1. Joe- 2+b (or 2+1b)
Micheal- 2b
2. Joe- 2+10=12
Micheal- 2x10=20
3. one distributes and the other just adds regularly.
2
Factors of 8: 1, 2, 4, 8
Factors of 6: 1, 2, 3, 6
Factors of 10: 1, 2, 5, 10
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.
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n = 11
k = 10,11
p = 1/2
M=rise over run
27 over 36 in lowest terms
Or 27/36