# Category: General

## Top 10 Popular Math Problems in 2016-2017

It’s been a year since I started this math blog!!

More than 500 problems were posted during a year (July 19th 2016-July 19th 2017).

I made a list of the 10 math problems on this blog that have the most views.

Can you solve all of them?

The level of difficulty among the top 10 problems.

【★★★】 Difficult (Final Exam Level)

【★★☆】 Standard(Midterm Exam Level)

【★☆☆】 Easy (Homework Level)

Read solution Add to solve later

## Even Perfect Numbers and Mersenne Prime Numbers

## Problem 496

Prove that if $2^n-1$ is a Mersenne prime number, then

\[N=2^{n-1}(2^n-1)\]
is a perfect number.

On the other hand, prove that every even perfect number $N$ can be written as $N=2^{n-1}(2^n-1)$ for some Mersenne prime number $2^n-1$.

Add to solve later## A One-Line Proof that there are Infinitely Many Prime Numbers

## Beautiful Formulas for pi=3.14…

The number $\pi$ is defined a s the ratio of a circle’s circumference $C$ to its diameter $d$:

\[\pi=\frac{C}{d}.\]

$\pi$ in decimal starts with 3.14… and never end.

I will show you several beautiful formulas for $\pi$.

Add to solve later## Mathematics About the Number 2017

Happy New Year 2017!!

Here is the list of mathematical facts about **the number 2017** that you can brag about to your friends or family as a math geek.