[IQ Challenge] - If a couple has two children, given that at least one of them is a girl, what is the probability...

[UltimaOnline]

[IQ Challenge]

Q1. If a couple has two children (born 1 year apart and have different names), given that at least one of them is a girl,
what is the probability that both children are girls?

Q2 If a couple has two children (born 1 year apart and have different names), given that at least one of them is a girl,
and that this girl is named Ah Lian, what is the probability that Ah Lian's sibling is also a girl?

Q3 Why are the correct answers to the Q1 & Q2 different?

 

[mojito]

This you must ask ChissyJohn bro. IQ and race.

 

[zhihau]

Wah piang eh... it’s probability question lah.

Q1. Given one is already XX, probability of getting another XX is 50%.

Q2. At random, child 1 to be XX is 50%, child 2 to be XX is another 50%, hence probability of 2 XX is 25%.

Q3. Then again, these are just standard punnet square distribution and you may have anomalies like XXX, XXY, trisomy of various combinations chromosome numbers, etc.

ps: names and years apart from each birth are irrelevant in these cases.

 

[sweetiepie]

[IQ Challenge]

Q1. If a couple has two children (born 1 year apart and have different names), given that at least one of them is a girl,
what is the probability that both children are girls?

Q2 If a couple has two children (born 1 year apart and have different names), given that at least one of them is a girl,
and that this girl is named Ah Lian, what is the probability that Ah Lian's sibling is also a girl?

Q3 Why are the correct answers to the Q1 & Q2 different?

KNN this is like a sg pool 3 face bet for home draw away KNN
home=both girl
draw= 1 boy 1 girl
away=both boy
At least 1 is a girl means away sure lose
so probability is 50% KNN

 

[bobby]

Depends on whether it is same sperm donor or not....

 

[ChristJohnny]

This you must ask ChissyJohn bro. IQ and race.

One thing I am sure - m&d cannot answer this question … or any other question.

IQ and Race

 

[UltimaOnline]

Ans to Q1 is 33%

Ans to Q2 is 50%

For Ans to Q3, see https://en.wikipedia.org/wiki/Boy_or_Girl_paradox

 

[UltimaOnline]

Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1.

Q1) ... ... the host, who knows what's behind all the doors, opens another door, say No. 3, to reveal a goat. The host then says to you, "Do you want to switch to the other closed door?". Is it to your advantage to switch your choice?

Q2) ... ... your friend in the audience, who doesn't know what's behind all the doors, runs onto the stage and opens another door, say No. 3, to reveal a goat. The host then says to you, "Do you want to switch to the other closed door?". Is it to your advantage to switch your choice?

Q3) Why are the correct answers to Q1 & Q2 different?