Puzzle Two women were selling marbles in the market place — one at three for a Rupee and other at two for a Rupee. One day both of then were obliged to return home when each had thirty marbles unsold. They put together the two lots of marbles and handing

# Problems

Problems and their Solving Approaches in Math

We all know that the derivative of $x^2$ is 2x. But what if someone proves it to be just x?