Permutations of divisible integers
Problem Statement: How many integers between 100 and 999, inclusive have the property that some permutation of its digits is a multiple...
Area of the triangle formed by joining three centers of a circle
Problem Statement: Circles with centers P,Q and R having radii 1,2 and 3 respectively, lie on the same side of line l and are tangent to...
Particle in square lattice
Problem statement: A square is drawn in a Cartesian coordinate plane with vertices at (2,2) , (-2,2) , (-2,-2) and (2,-2). A particle...
Table coin problem
Problem Statement: There are eight people sitting on a round table, they all flip a coin simultaneously, if head shows up the person is...
Possible paths in a nxn grid
Problem Statement: You are standing on the point A in a city where roads are represented as lines and each corner is a stop. You need to...
43,252,003,274,489,856,000 combinations of a 3x3 rubik's cube...
We all are familiar with rubik's cube. It is one of the most famous puzzle and there are a lot of competitions held every year in which...
1 + 2 + 3 + ... = -1/12
What a normal person would think of this sum 1 + 2 + 3 + 4....... ? Everyone will agree that the sum is increasing and increasing all the...
Riemann hypothesis
Want to earn a million dollar? Try Riemann hypothesis ! It is one of the most famous problem in mathematics and simple enough to be...