# Mathematical Problem Solving Sprint Hello every $\int_{-\infty}^\infty \frac{1}{\pi(1+x^2)}dx$.

Now, exactly $22$ years ago, Mongolia held its first direct presidential elections. To celebrate this, I would like to propose a new contest: $\large{\text{The Problem Solving Sprint!}}$

Rules: A member posts a link to a problem of their choice. Then, another member who has solved that problem must comment in the solutions section to prove that he has solved the said problem, and can then choose another challenging problem for others to solve. One may not nominate two problems in a row, however, the problem's author is allowed to participate.

The point of this is to show some challenging problems which you wouldn't otherwise want to solve/ try. The person who has nominated the most problems, as well as the problem author whose problems were selected the most times, will win the contest.

The contest will end when one person has nominated $e^{i\pi}+7$ problems. No further entries will be accepted.

The first problem is my Cards. Why Does It Have To Be Cards?. Try and solve it and then post a link to another problem!

Do like and reshare, so that more people can participate.

Note: The problems must either be in Algebra, Number Theory, Combinatorics, Calculus or Geometry. Note by A Former Brilliant Member
6 years, 1 month ago

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

• Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
• Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
• Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in $$ ... $$ or $ ... $ to ensure proper formatting.
2 \times 3 $2 \times 3$
2^{34} $2^{34}$
a_{i-1} $a_{i-1}$
\frac{2}{3} $\frac{2}{3}$
\sqrt{2} $\sqrt{2}$
\sum_{i=1}^3 $\sum_{i=1}^3$
\sin \theta $\sin \theta$
\boxed{123} $\boxed{123}$