1
vote
1answer
62 views

Is there closed form for $(1-p)(1-p^2)(1-p^3)…$ or its Taylor expansion?

I was considering the following problem: Somebody uses a backup for something (e.g. backups a file) and the backup is equally reliable as original storage. The storage is not perfectly reliable and ...
1
vote
4answers
79 views

Probability of choosing a subset of elements where each element has a different probability

I am trying to write a C++ program to do this but nobody on Stackoverflow can seem to help me so I thought I'd try to do it myself with some help from you guys. My post on Stackoverflow can be found ...
2
votes
3answers
95 views

I flip M coins, my opponent flips N coins. Who has more heads wins. Is there a closed form for probability?

In this game, I flip M fair coins and my opponent flips N coins. If I get more heads from my coins than my opponent, I win, otherwise I lose. I wish to know the probability that I win the game. I ...
0
votes
1answer
190 views

Find the probability that splitting the unit interval into three random segments results in the sides of a triangle.

I found the question here. The precise problem is The unit interval is broken at two randomly chosen points along its length. Show that the probability that the lengths of the resulting three ...
1
vote
1answer
66 views

Estimate the scale of the power series with Poisson pdf-like terms

Sorry to bother you, but I guess that this question is not appropriate for MO, so I repost it here hoping that someone could give me a clue. I would like to have an estimate for the series $$P(t) = ...
1
vote
2answers
263 views

Closed form for Exponential Conditional Expected Value & Variance

I am wondering if there is a closed form for finding the expected value or variance for a conditional exponential distribution. For example: $$ E(X|x > a) $$ where X is exponential with mean ...
0
votes
0answers
49 views

Need help with probability closed form expression

Probability that a sequence of x coin flips will contain TH. How exactly would I approach this problem? Just need hints to direct me in the right direction.
2
votes
1answer
114 views

Probability of getting some kinds of balls

Suppose we have $N$ kinds of colored balls, and there are an infinite number of each kind. Now we'd like to draw $m(m>N)$ balls from them. How to calculate the probability P(m,n), which is the ...
15
votes
2answers
333 views

Who has the upper hand in a generalized game of Risk?

So, I played a game of Risk the other day for the first time since I was very little. I was frustrated to discover that I couldn't compute (at least not in my head) whether the attacker or the ...