Muhammad R. answered • 02/08/21
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There 3276 combinations of three students.
George S.
Kelly M, In many cases, using a Counting Rule can help answer the question: How many different ways are there to ....? Your question seeks "Combinations" (and not "Permutations"). As such, it asks for how many different groups are there, where the order within the group does not count. For example, with Combinations, a foursome group with Student 4, Student 5, Student 8 and Student 2 is the same as one with Student 5, Student 2, Student 8 and Student 4. With Permutations, the order within the group makes a difference. So, the above foursome groups are different because the students, although the same within each group, are in a different order. Counting Rule Formula for Combinations: n! / (r!)(n-r)! where: n = total number of objects (students) to be selected from = 28 r = number of objects (students) selected = 3 ! = factorial Thus, 28! / (3!)(28-3)! = (28)(27)(26)(25)....(1) / (3)(2)(1)(25)....(1) which reduces to (28)(27)(26) / (3)(2)(1) = 19656 / 6 = 3276
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02/09/21
Kelly M.
thank you!
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02/10/21
Muhammad R.
Kelly, it's a combination question. 28C3. George has already provided a detailed answer for it.
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02/10/21
Fiona B.
where does the 6 come from for the last step of the divide?
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07/05/21
Kelly M.
How did you get that?02/08/21