JiK's user avatar
JiK's user avatar
JiK's user avatar
JiK
  • Member for 10 years, 6 months
  • Last seen this week
53 votes
Accepted

A beautiful game of gold and silver coins

34 votes

Why do I get two different answers for this counting problem?

25 votes

Best strategy to pick a lock which opens if at least two of its three decimal digit wheels are dialed correctly?

25 votes

Expected Value of a Determinant

19 votes

"Simple" beautiful math proof

15 votes
Accepted

How to make the encoding of symbols needs only 1.58496 bits/symbol as carried out in theory?

13 votes

U-substitution for integral of 1/(1+e^x)dx. What am I doing wrong?

12 votes
Accepted

Find integral when $dx$ is in the numerator

12 votes
Accepted

why does commutativity of addition fail for infinite sums?

12 votes

How to make a perpendicular construction in 3 moves?

12 votes

Is it technically incorrect to write proofs forward?

12 votes

Minimum point of $x^2+y^2$ given that $x+y=10$

12 votes

If the order in a set doesn’t matter, can we change order of, say, $\Bbb{N}$?

11 votes

Most efficient strategy for guessing outcome of (fair) dice roll?

11 votes

If $p$ and $q$ are prime numbers larger than $2$, then $pq + 1 $ is never prime

10 votes

Showing that a complex number $z$ satisfies $|z|\leq 1$ given a certain condition

10 votes
Accepted

Why does differentiating a polynomial reduce its degree by $1$?

8 votes
Accepted

Why does Fixed Point Iteration work?

8 votes

How do we know that common rearrangement proofs of the Pythagorean theorem work for any right triangle?

6 votes

One of two independent flip sequences reaches two heads simultaneously. What is the distribution of others tosses.

6 votes

If $P(A) \neq 0$ and $P(B) \neq 0$, then $P(B|A) \geq P(B)$ is equivalent to $P(A|B) \geq P(A)$

6 votes

Matrix with zeros on diagonal and ones in other places is invertible

6 votes

What will be the value of the following determinant without expanding it?

6 votes

"Proof" that $1-1+1-1+\cdots=\frac{1}{2}$ and related conclusion that $\zeta(2)=\frac{\pi^2}{6}.$

6 votes

"Here's a cool problem": a collection of short questions with clever solutions

6 votes
Accepted

Conditions on solutions of a diophantine equation.

6 votes

Example of a set of real numbers $S$ where $\inf S = \sup S$?

5 votes

Define an infinite subset of primes such that the sum of reciprocals converges

5 votes

Probability that the ball drawn from $n$th urn is white

4 votes

$66$ points in $100$ shots.

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