Combinations! How many......... 1. The problem statement, all variables and given/known data How many letter combinations with 9 letters are you able to make with following letters : M-A-T-E-M-A-T-I-K? 2. Relevant equations Well its pretty obvious you need to use Combinations. Please explain how you solve this problem, don't write use combinations . I need to know how you think and from which angle you "attack" the problem.