Let us try to answer this 'WHY' in the question quoted by WasimAkramKhan above. While the keywords present in the question statement are of help in clearing the doubt about whether Order Matters or not, nothing beats conceptual understanding of WHY order matters in a particular case and not in another. It is therefore a selection (combination) question. This also probably explains why WasimAkramKhan asked the follow-up question, which had the keyword 'choose'. So, the list of keywords provided by I3igDmsu needs to be corrected in this regard. However, please note that the words 'Pick' and 'Choose' indicate that order DOES NOT matter. He is right that being aware of certain keywords helps you determine whether Order Matters in a question or not. I3igDmsu has done a great job of giving sample questions where Order Matters I think that in this example order doesn't matter. This is something that has helped me, hopefully it helps others. *In how many ways can a sorority of 20 members select a president, vice president and treasury, assuming that the same person cannot hold more than one office.Īll of these questions are answered using the permutation formula: \(nPr=\frac\) How many different ways can the teacher choose the demonstrators given the following conditions. * A teacher has 15 students and 5 are to be chosen to give demonstrations. *How many different arrangements can be made using two of the letters of the word TEXAS if no letter is to be used more than once? *If a softball league has 10 teams, how many different end of the season rankings are possible? (Assume no ties). *In how many ways can 8 CD’s be arranged on a shelf? If order matters then use the permutation formula. Looking for key words in the sentence like:Īnd many others signify that order matters. The easiest way that I have found to use the permutation formula is when the question states that order matters. The definitions of permutations and combinations are are sometimes not clear to beginners. I was struggling with when to use the permutation formula and when to use the combination formula in various problems.
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