What is Combination and What is the Formula for nCr? https://www.youtube.com/watch?v=FEr4RaEOLZY Combinations Definition: Each of the different groups or selections which can be formed by taking some or all of a number of objects, irrespective of their arrangements, is called a combination. Notation: The number of all combinations of n things, taken r at a time is denoted … [Read more...] about What is Combination and What is the Formula for nCr?