What does the Subsets of set of real numbers means? And what does it consists of?

If there are 5 dishes, they can be relished in any order at a time. In permutation, it should be in a particular order. In combination, the order does not matter. Take 3 letters a, b, and c. The possible ways of pairing any two letters are ab, bc, ac, ba…

The fundamental counting principle is a rule that is used to count the total number of possible outcomes in a given situation.