Number System Archive

How I chanced upon Factorial Function

Today we will see how Piyush Goel(the contributor of this article) discovered something while playing with numbers. Here is the story contributed by him: One day while sitting idle, and having nothing important to do I was

How to find the largest power of a number that divides a factorial number?

Factorial Factorial of a number or n! is the product of n consecutive natural numbers starting from 1 to n. Hence, 4! is nothing but 1x2x3x4 = 24 Common Type of Questions on Factorials Two types of

How many zeros are there at the end of 100 factorial?

How many zeros at the end of 100 factorial? How many trailing zeros in 1000 factorial? Do you get baffled by questions like these? How useful is calculator in solving this problem? Sadly, calculator is not of much help

How to Convert from Other Number Bases to Decimal System?

Questions on conversion of numbers in some base to some other base is very common in competitive examination. Here in this post I present a simple technique to help you do such conversions. First, let us understand

Solving Number Series Questions Can Be So Simple…Learn How?

In the last article, I had discussed various types of series. Today I will discuss how to approach a series problem once you have identified what kind it is. Let me be honest. There is no algorithm

Do you get terrified by Number Series Questions?

‘Number Series’ or ‘number sequence’ is an integral part of Quantitative Aptitude Section in various competitive examinations like IBPS Bank exams, SSC, RAIL and so on. I’ve come across many students who get petrified by looking at

Learn to test whether a given number is prime number or not

By looking at a number do you wonder whether it’s a prime number or not? Is it always complicated for you to figure out the answer? If the answer to above questions is yes, go ahead and

Do You Know the Sum of All Positive Integers till Infinity, be Prepared for a Shock After Knowing the Answer

This is one of the most amusing mathematics trick pulled off by someone. If you understand basics of numbers, your jaw will drop at the output of this mathematics formulation. So here we go – What do

Shortcut to Find the Fourth Power of any Two Digit Number

In this article we will explore a shortcut to find the fourth power of any 2 digit number. The approach will be similar to the shortcut to find the cube of any 2 digit number. I strongly


In CAT and other MBA entrance examinations you get questions based on cyclicity every year. Here we are explaining in details the concept of cyclicity and how it should be used for solving problems. To understand cyclicity