# Math Puzzles

## Brain teaser

My friend just finished a job interview and was asked the following question that I thought I’d share with you (it’s a somewhat common puzzle): You are given 8 balls, 7 of which are the same weight and 1 which is heavier than the rest. Using a balance, what is the minimum number of weightings …

## Making change

Consider the following hypothetical situation: You are a cashier and you have to give the customer \$0.40 in change, however, you have no nickels left in your till. The goal is to minimize the number of coins that the customer receives. How do you do it? Well this actually happened, and the process the cashier …

## Topological Poker

This is interesting. RandomPairing over at the math subreddit listed some rules for a game called Topological Poker (aka Dicks and Hoes), which I assume he created himself. [I did a google search for “Topological Poker” and only got the subreddit, and then did a search for “Dicks and Hoes” and got a bunch of …

## Math alarm clock for your phone

Nice! That’ll keep me awake ðŸ˜€

## Math clock

Do the math! I dare you…

Hmmm…

## Identical lottery draw

In Bulgaria’s national lottery, the same six winning numbers were drawn twice in a row. Minister Svilen Neikov ordered an investigation after the numbers 4, 15, 23, 24, 35, and 42 were selected, in a different order, by a machine live on television on September 6th and 10th. Some thought the results were manipulated, however …

## A Friendly Chat About Whether 0.999… = 1

Via reddit I stumbled upon this site which talks about something called hyperreal numbers and claims that in this theory, the equation 0.999… = 1 is false. For those who follow the internet, the question of whether 0.999…=1 has come up a quadbrazillion times on practically every math related forum and even the non-math ones. …

## Silly prediction quiz

Take this silly quiz and we will predict your all time favorite tv show! First pick a number from 1 to 9. Multiply by 3. Add 3. Multiply by 3 again. Add the two digits together. Now you should get a number and find it in the chart below! 1. Smallville 2. Grey’s Anatomy3. Supernatural …