dREaM
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 Jan 31 comment Combinatoric problem - roundtable Oh ok, this is a simple application of burnside's enumeration theorem. Jan 31 comment Sequence $\left\{ x_{n}\right\} _{n\geq1}$ s.t $\left|x_{n+1}-x_{n}\right|<2^{-n}$ for all $n\geq N$ , does this imply convergence? Oh yes, my bad. thanks. Jan 31 revised Sequence $\left\{ x_{n}\right\} _{n\geq1}$ s.t $\left|x_{n+1}-x_{n}\right|<2^{-n}$ for all $n\geq N$ , does this imply convergence? added 10 characters in body Jan 31 comment Combinatoric problem - roundtable is it $24!{}{}{}{}{}$ ? Jan 31 answered Sequence $\left\{ x_{n}\right\} _{n\geq1}$ s.t $\left|x_{n+1}-x_{n}\right|<2^{-n}$ for all $n\geq N$ , does this imply convergence? Jan 31 comment Double sequence, if $(x_m)_m$ and $(y_n)_n$ converge, then they have the same limit? I don't think this is enough. Jan 31 answered Sequence $sin(\alpha * n)$ limit problem Jan 31 revised Give a complete set of equivalence class representatives for an equivalence relation on the natural numbers (including zero) added 1 character in body Jan 31 comment can we find a $k_4$ colored with 1 color in a $k_8$ which is colored with just 2 colors? You're welcome, happy to help. Jan 31 revised can we find a $k_4$ colored with 1 color in a $k_8$ which is colored with just 2 colors? added 349 characters in body Jan 31 answered can we find a $k_4$ colored with 1 color in a $k_8$ which is colored with just 2 colors? Jan 31 answered Give a complete set of equivalence class representatives for an equivalence relation on the natural numbers (including zero) Jan 31 comment Prove that a connected graph with $n$ vertices is a tree iff it has $n-1$ edges. Congratulations, you are the 9999 user to ask this question. Click here to find one of many duplicates. Jan 31 answered Let R be a ring such that $a^2 = a$ , $\forall a$ $\in R$ . Prove that R is commutative. Jan 29 comment Of 100 people seated at a round table, more than half are women. Prove that there exist two women who are seated diametrically opposite each other. It does, but how does that help for the problem? Jan 28 answered Show that $A \subset B \implies A \cap B = A$ Jan 28 comment Why do we use nCk when determining numbers of favorable outcomes of coin tosses? I posted a link in my previous comment, the word "this". Jan 28 comment Why do we use nCk when determining numbers of favorable outcomes of coin tosses? Hopefully this helps Jan 28 comment Why do we use nCk when determining numbers of favorable outcomes of coin tosses? I meant $n$ ways to pick a flip which is going to be heads, but this is probably explained better elsewhere, let me look. Jan 28 comment Why do we use nCk when determining numbers of favorable outcomes of coin tosses? Oh ok, there are $n$ ways to choose the first element, $n-1$ for the second and so on. SO $n\times(n-1)\dots \time(n-k+1)=\frac{n!}{(n-k)!}$ in total. However you have counted each outcome $k!$ times,because the order can be swapped without changing the elements. So answer is $\frac{n!}{k!(n-k)!}$.