Probability of 9-ball on Break
- Thread starter Jen_Cen
- Start date
Are you saying we should consider "mixed gender" as one possible type of combination, not as two specific possible combinations? OK, but then the ratio of girl/girl, boy/boy and mixed gender families is 1/4, 1/4, 1/2, not 1/3, 1/3, 1/3. So boy/boy plus mixed = 3/4 and boy/boy is 1/3 of that.
Here's another way to look at it: If mixed is a type then "same" is a type and there are really only two groups, 1/2 each. All the pairs with boys includes all of the mixed group but only half of the same group (same = 1/3).
Flip two coins a bunch of times or flip one coin a bunch of times in pairs or pick pairs of coins randomly out of two pockets. The number of pairs with 2 heads will be 1/3 of the total pairs with any heads.
pj
chgo
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Drew said:
Well then, you must be right! We've all explained it in laymen's terms, and I can assure you the math checks out. The question is worded in a particular manner and that wording is correct.
Let's play a second game. 3 labelled doors, 1,2 & 3. Two of the doors have goats behind them, the other a car. Choose a door. I'll now open a door that contains a goat.
Two questions for you:
1) What are the odds of your pre-selected door having a car?
2) What are the odds of the remaining door having a car?
Despite all the intuition you may apply to the problem... the answers are 1/3 and 2/3 respectively. This is a similar concept, it's how revealed information affect probability... it's a well proven mathematical concept.