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comment Finding $P(A \cap D)$ when $P(A), P(B), P(C), P(D), P(A \cap B), P(A \cap D) + P(B \cap C)$ is known
Draw the simplest Venn diagram that has nontrivial values for the above, and see what you can manipulate while keeping the values constant.
Jan
31
comment can we find a $k_4$ colored with 1 color in a $k_8$ which is colored with just 2 colors?
What is the minimum size of a set of edges such that each $K_4$ contains at least one edge in the set?
Jan
28
awarded  Tumbleweed
Jan
21
asked Induced subgraphs of a hypercube
Jan
20
comment How can I tell which one of these numbers is greater?
Your sum is less than 9E99 times $(9E99)^9$. This should give you a start
Jan
14
comment Spivak's Limit Example
Pay close attention to the difference between < and $\le$ in the definition. Understand that $0<|x-a|$ means that $x\ne a$. (This is going to continue to be important in analysis.)
Jan
10
revised How was the expression relating two general solutions to $x\frac{\partial u}{\partial x}+2\frac{\partial u}{\partial y}- 2u = 0$ obtained?
added 212 characters in body
Jan
10
answered How was the expression relating two general solutions to $x\frac{\partial u}{\partial x}+2\frac{\partial u}{\partial y}- 2u = 0$ obtained?
Jan
10
comment Continuity at a point.
Are you sure it is true for all $m$ and $n$? Hint: $x^3$ is odd.
Jan
10
comment How was the expression relating two general solutions to $x\frac{\partial u}{\partial x}+2\frac{\partial u}{\partial y}- 2u = 0$ obtained?
Equate the two solutions.
Jan
9
comment A coin has ever-decreasing probability of landing heads on the nth toss. When can we expect it to land on heads in finite time?
Something like that should work. (I'm not the person asking the question, and I am not sure he knows exactly what he wants.)
Jan
9
comment A coin has ever-decreasing probability of landing heads on the nth toss. When can we expect it to land on heads in finite time?
This, however is not the same as the expected time before getting a head being finite. If we let $p(n)=1/2$ if $n$ is a power of two and 0 otherwise (I'm ignoring the monotinicity condition for simplicity sake, you can spread the probabilities to taste as long as the probabilities of reaching a power of two is about the same) then $\sum p(n)$ diverges, so we are guaranteed to get a head, but the expected time before a head is achieved is not finite. This is a thinly disguised St Petersburg paradox.
Jan
5
accepted Absolute Continuity of the sum of two Cantor random variables
Jan
5
comment Absolute Continuity of the sum of two Cantor random variables
Thanks. (The answer to your exercise is that the $\ne$ becomes an $=$ in (2)). This is partly what kept me from looking too closely at the limit $t\to \infty$ of the characteristic function.
Jan
5
comment Integer programming model not working
Take the given solution and plug it in to the weight constraints you have written and you will find that the constraints are satisfied. (Hint: Those constraints are where your problem is (as well as Doug's first comment))
Jan
2
revised Absolute Continuity of the sum of two Cantor random variables
Mostly I said uniformly twice when I meant absolutely. Early senility. Minor other tweaks.
Jan
2
awarded  Revival
Jan
1
revised Can you simulate from a cantor distribution?
Fixed missing 2
Jan
1
asked Absolute Continuity of the sum of two Cantor random variables
Jan
1
answered Can you simulate from a cantor distribution?