# Tag Archives: puzzles

Question: What is one number that’s divisible by everything? and Question: What number is divisible by all 9 numbers 1 to 9? Read more »

## How do we know the earth is rotating, and it is not the stars moving around the earth

How can you tell that the earth is rotating about an axis, and that the stars aren’t instead just moving around the earth? Read more »

## What is a quick way to add the numbers from 1 to 10, and how does it work?

You can add the integers from 1 to 10 by hand, but what if you need to add from 1 to 1000? The shortcut for adding Read more »

## Are all three digit numbers divisible by eleven and other questions

For example one searcher wonders if all three digit numbers are divisible by eleven. The answer is Read more »

## How to open a Master combination lock without the combo

So if you must open a locked Master combination lock then take an inspiration from MacGyver Read more »

## How can you quickly tell if a number is divisible by 3 and why this trick works

So is 151515151515151515 divisible by 3? I can quickly tell you yes. The trick is to Read more »

## It is a matter of life and death. The true story of how to get rid of ghosts from a haunted house.

Even if you don’t believe in ghosts, read this story, or skip to the end. You may save someones life. Truly. Read more »

## Why anecdotal evidence is important

The most important statement a scientist can make is “Huh, that doesn’t make sense. That shouldn’t have happened.” It is a sign post that new understanding and maybe even pushing the frontiers of science lies ahead. Read more »

## How to win the lottery more than once

The trick itself is ridiculously simple. (Srivastava would later teach it to his 8-year-old daughter.) Each ticket contained eight tic-tac-toe boards, and each space on those boards—72 in all—contained an exposed number Read more »