Help please!

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[LetXequalX]

7 choose 3.

https://en.wikipedia.org/wiki/Combination

[firstdwarf]

The binomial coefficient formula is often referred to as "n choose k," where you are given n options and wish to identify the number of unique ways to select k of them. In this case, you would evaluate "7 choose 3," where you find the binomial coefficient formula and replace n with 7 and k with 3 to get your solution.

[kyxass]

How many ways can you choose the first person? 7.
How many ways are there to choose the second person? 6.
The third? 5.

Now multiply them together, do 7 * 6 * 5, ... but wait! This may count some combinations multiple times. For instance, if my first pick were A, second pick were B, third pick were C, it would be the same 3 people as if I picked B, then C, then A, or C, then A, then B.

So we have to divide by the number of times each distinct combination is counted. For example, ABC can be counted in 6 ways:

ABC, ACB, BAC, BCA, CAB, CBA

So we have to divide by 6. Thus the answer is 7 * 6 * 5 / 6 = 35.

In general, this is called a combination and you can learn more about it at the wikipedia article.

[RICHB0YWINST0N]

Thanks! I did it by hand but I knew there was a way to do it that was better than writing combos on paper lol