A teacher gave a student the task of adding āNā natural numbers starting from 1. After a while, the student reported his result as 700. The teacher replied that his result was wrong. The student realized that
he had added one number twice by mistake. Find the sum of the digits of the number which the student had added twice.
Do not worry about your difficulties in mathematics, I assure you that mine are greater.
Albert Einstein
Pure mathematics is the world's best game. It is more absorbing than chess, more of a gamble than poker, and lasts longer than Monopoly. It's free. It can be played anywhere - Archimedes did it in a bathtub.