Hey everyone, I have an assignment on Permutations and Combinations and was wondering if some of you could go over my work and ensure that I have this aced. I really need to get my math mark up for University admissions so I need to ace this assignment. Thanks a lot for your help! -Jonathan 1) In how many distinguishable ways can the letters of the word MISSISSIPPI be arranged? Number of distinguishable arrangements = 11!/(4!4!2!) = 34,650 2) Find the number of ways of arranging all the letters AAABBBCCDD in a row so that no two A's are side-by-side. Number of arrangements = 7!/(3!3!2!2!) = 35 what I did: I paired the letter A up with another letter, by viewing them as 1 letter no 2 A's would ever be side by side. This makes 7 letters, and then I divided out the repeats. 3) How many distinguishable four letter arrangements can be made from teh letters of the word MISSISSIPPI? Number of four letter arrangements = (ways with no repeats) + (ways with all 4 letters repeated) + (ways with 2 doubles) + (ways with a triple and a single) = (4c4)x4 + (2c1) + (3c2)x(4!/2!2!) + (2c1)(1c1)x(4!/3!) = 24 + 2 + 18 + 8 = 52 *****If it is unclear what I have done hear please ask me***** Those are the first 3 questions out of 5. I want to make sure I'm on the right track before I finish the next 2, as they are significantly more difficult.