Permutations and Combinations

What “Permutations and Combinations” begins with

100 MATHEMATICS vEvery body of discovery is mathematical in form because there is no other guidance we can have – DARWINv 6.1 Introduction Suppose you have a suitcase with a number lock. The lock can be opened if 4 specific digits are arranged in a particular sequence with no repetition. Some how, you have forgotten this specific sequence of digits.