Answer:
B. 45
Step-by-step explanation:
Just a pure guess. I got roasted a lot of times :( so I just guessed
126 groups can be made.
Combinations are selections made by taking some or all of a number of objects, irrespective of their arrangements. The number of combinations of n different things taken r at a time, denoted by
n^C_r = n!/ r!( n-r)!
Suppose we have a set of 6 letters { A,B,C,D,E,F}. In how many ways can we select a group of 3 letters from this set? Suppose we find the number of arrangements of 3 letters possible from those 6 letters. That number would be 6P3
. Consider the permutations that contain the letters A, B, and C. These are 3! = 6 ways, namely ABC, ACB, BAC, BCA, CAB, and CBA.
We calculate combinations using the combinations formula, and by using factorials and in terms of permutations. In general, suppose we have n things available to us, and we want to find the number of ways in which we can select r things out of these n things. We first find the number of all the permutations of these n things taken r at a time. That number would be
nPr.
Given:
n= 9, r=5
n^C_r= 9!/ 5! * 4!
= 9*8*7*6/ 4*3*2
=126
Hence, there are 126 ways.
Learn more about combination here:
https://brainly.com/question/28065038
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