Do not be rude some people may not have the same level of intelligence as you do. Things that may seem easy to you can be difficult to others. I like to think this website is friendly to children as well as adults. For all that you know, the person who asked that qustion could be 7 years old. Maybe they have trouble with mathematics and they came on this website for help. It is right to call someone an idiot as you did. You do not know what circumstances prompted them to ask this question. Here is a helpful article about how to be nice to people who you do not think have the same level of intelligence as you, but who ever could do that, because you are clearly a genius. http://personalself.com/how-to-deal-with-stupid-people/