1. ## partition law

Two basketball players throw a ball into the basket till the first hit.
The probability for the first player tol hit the target is 5%, but for the second - 15%.
What is the partition law for the number of attempts both player made.

thanks for help.

2. ## Re: partition law

Are you asking "how can I look at this problem and immediately know the aswer without doing any calculation?" I have no idea. But sitting down and doing some calculations might well show a pattern.

The first player will win on the first throw .05 of the time.
The second player will win on his first throw if the first player misses and he hits: (.95)(.15)
The first player will win on the second throw if the first player misses on the first try, second player misses, first player hits on second try: [tex](.95)(.85)(.05)
The second player will win on his second throw if the first player misses, second player misses, first player misses, second player hits: [tex](.95)(.85)(.95)(.15)
The first player will win on the third throw if they both miss twice and the he hits: (.95)(.85)(95)(.85)(.05)
The second player will win on the third throwif they bothiss twice, the first player misses, the second player hits: (.95)(.85)(.95)(.85)(.95)(.15)

So far for the first player we have
1: .05= ((.95)(.05))^0(.05)
2: .95(.85)(.05)= ((.95)(.85)^1)(.05)
3: .95(.85)(.95)(.85)(.05)= ((.95)(.85))^2(.05)
See a pattern?

3. ## Re: partition law

Originally Posted by HallsofIvy
Are you asking "how can I look at this problem and immediately know the aswer without doing any calculation?" I have no idea. But sitting down and doing some calculations might well show a pattern.

The first player will win on the first throw .05 of the time.
The second player will win on his first throw if the first player misses and he hits: (.95)(.15)
The first player will win on the second throw if the first player misses on the first try, second player misses, first player hits on second try: [tex](.95)(.85)(.05)
The second player will win on his second throw if the first player misses, second player misses, first player misses, second player hits: [tex](.95)(.85)(.95)(.15)
The first player will win on the third throw if they both miss twice and the he hits: (.95)(.85)(95)(.85)(.05)
The second player will win on the third throwif they bothiss twice, the first player misses, the second player hits: (.95)(.85)(.95)(.85)(.95)(.15)

So far for the first player we have
1: .05= ((.95)(.05))^0(.05)
2: .95(.85)(.05)= ((.95)(.85)^1)(.05)
3: .95(.85)(.95)(.85)(.05)= ((.95)(.85))^2(.05)
See a pattern?
Thanks for this.
But I don't know how to write this as a parition law.