dREaM
Reputation
35,173
97/100 score
 Nov 22 answered How to prove that a connected graph with $|V| -1= |E|$ is a tree? Nov 22 answered Graph theory notational issue? What does $|N(X)|$ mean? Nov 22 answered Prove that $b^5=1$ Nov 2 asked If $A$ and $B$ are summands of injective module $Q$ then $A+B$ is a sumand of $Q$. Nov 2 answered Which tuple of arithmetic progression sums does the given integer fall into? Nov 2 asked Composition of category equivalence and limit creating functor preserves limit Nov 2 answered How many times must we roll a single die in order to get the same score $n$ times? Nov 2 answered Which of the following powers is bigger: $2^{41}$ or $3^{24}$? Nov 1 asked If $P$ is projective and $A,B$ are direct summands of $P$ then $A\cap B$ is a direct summand of $P$ Nov 1 asked Proving $\Bbb Z_p$ has no projective cover. Nov 1 asked Two quotients of projective modules are equal, prove the crossed direct sums of the projective modules and kernels are isomorphic. (Schanuel's Lemma) Oct 29 answered Every open set in $\mathbb{R}$ is the countable union of rational open intervals Oct 15 answered If $3|n^3$, does $3|n$? Oct 13 answered How many six-digit numbers are there such that their sum of digits is $\le 47$? Oct 8 answered The product of $2×653×733×977$ has each digit exactly once except for one, which one is it? Oct 8 answered $\frac{(mn)!}{m!(n!)^m}\in\mathbb N^*$? Oct 7 answered Coloring the windmill Oct 7 answered Let $S$ be a semigroup that satisfies the property $\forall a \in S, aS=S \wedge Sa=S$. Show that $S$ is a group. Oct 4 answered Given a string $ab$ and string length $n$, how can I prove that $|\{ (x,y) : x\text{ is index of } a, y\text{ is index of } b , x < y \}| \le n^2/4$ Oct 4 answered For $1\leq n\leq 100$ how many integers are there such that $\frac{n}{n+1}$ is a repeating decimal?