9/10/2023 0 Comments Permutation order matters![]() Probability of you getting at least 2 heads is 2 outcomes / 4 Combinations (with Repetition) = 0.5. If you are looking for "at least 2 Heads", 2 options match: HHH and HHT (order not important). These are (because order is not important): HHH, HHT, HTT, TTT If the question is "If you throw a 2-sided coin (N=2), R times, how many times can you get at least 2 heads?", you are looking for Combination (order is not important) with Repetition where "HHT" and "THH" are same outcomes (combination).Ĭombination with Repetition formula is the most complicated (and annoying to remember): (R+N-1)! / R!(N-1)!įor 3 2-sided coin tosses (R=3, N=2), Combination with Repetition: (3+2-1)! / 3!(2-1)! = 24 / 6 = 4 ![]() Probability of "at least 2 heads in a row" is 3/8th (0.375) A permutation is a way to select a part of a collection, or a set of things in which the order matters and it is exactly these cases in which our permutation calculator can help you. In these, "at-least-2 Heads in a row" permutations are: HHH, HHT, THH - 3. ![]() C(10,3) 10/73 (10 × 9 × 8)/(3 × 2 × 1) 5 × 3 × 8 2) In how many ways can coach Johnson select 5 young women for the basketball team if 15 players try out Order does not matter among selected team members. Again, I look at book examples and this permutation example has me confused: Suppose that a saleswoman has to visit eight different cities. I try using this knowledge after reading a question but never know for certain. order matters with permutations but NOT combinations. Permutation with Repetition is the simplest of them all:ģ tosses of 2-sided coin is 2 to power of 3 or 8 Permutations possible. pizza The order of choosing toppings does not matter so it is a combination not permutation solution. permutations are larger than combinations. If the question is "How many ways a series of R coin tosses (N=2 sides) can go? Of these, how many will have 2 Heads in the row?", you are looking for Permutation with Repetition where "HHT" is different outcome from "THH". *Probably the best page that summarizes the Combination vs Premutation with or without Repetition * ![]() Coin toss series can be viewed, depending on what you want to know, as either "combination" or "permutation" but in all cases "with repetition" (meaning same side can occur again and again). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |