Every one of us should have a clear idea about what is permutation and what is combination. I insist on saying this only because i have seen many people using these two words interchangeably. Let us understand the difference between permutation and combination though an example.
Suppose you want to unlock a number lock and let the unlock code be 1234. OK, now u want to unlock your baggage and u know that the unlock code contains the numbers 1,2,3 and 4 and u r not sure about the exact number.Well,as you …