shavarna wrote:
I thought that order does not matter for when child is born, therefore
Total number of events = 5 (explained below)
0 Boys 4 Girls
1 Boy 3 Girls
2 Boys 2 Girls
3 Boys 1 Girl
4 Boys 0 Girl
Probability (2 B and 2 G exactly) = 1/5
Not sure where I am assuming and making a mistake.
Hi shavarna,
The 5 options you've listed are NOT all equally likely, so you would have to do a bit more work to get to the correct answer. There are a couple of ways to answer this question:
1) You could make a table of all the options (since each child could be a boy or a girl, there are only 2^4 = 16 possible outcomes) and determine all the ways to get 2 boys and 2 girls
or
2) You can do the math
Here's the math approach:
Since each child has an equal chance of ending up as a boy or girl, there are 2^4 possibilities = 16 possibilities. It also doesn't matter which 2 of the 4 children are boys, so you can treat this part of the question as a combination formula question...
4c2 = 4!/[2!2!] = 6 ways to get 2 boys and 2 girls out of 16 possibilities. 6/16 = 3/8
Final Answer =
GMAT assassins aren't born, they're made,
Rich
But that's also valid method right as nowhere stated in question that in how many different way this is possible.
______________________________
Press +1 Kudos if my post helped you a little and help me to ulcock the tests Wish you all success
I'd appreciate learning about the grammatical errors in my posts
Please let me know if I'm wrong somewhere and help me to learn