The crisp new dollar bill that I have just taken from my wallet bears the serial number 24598176. It’s easy to tell that the number is exactly divisible by 2 but not by 5. Is it divisible by 3? by 4?

Ravi Handa,an alumnus of IIT Kharagpur suggests three simple rules to find out divisibility of numbers. The concept of 'divide and conquer', derived from the Latin phrase 'Divide et impera', was put ...

It’s easy to tell if a given whole number is divisible by 2. Just check whether the last digit is even. There are also simple rules to determine whether a number is ...