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SAT Math 1.1 Numbers and Operations. How many combinations of beverage and cereal can be made?
SAT Math 2.3 Statistics and Probability 229 Views
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SAT Math 2.3 Statistics and Probability
SAT Math 2.3 Statistics and Probability
Transcript
- 00:02
Here’s your shmoop du jour, brought to you by Permutations.
- 00:06
The preferred hairstyle of mathematicians.
- 00:09
Six students are arranged in a row.
- 00:12
How many different ways can this happen? And here are the potential answers…
- 00:18
When we are arranging students in a row, we are counting permutations.
Full Transcript
- 00:26
The easy way to solve one of these permutation problems is
- 00:28
to simply take the factorial of the number we are ordering.
- 00:35
In this case…it's 6.
- 00:37
We start with 6 spaces to place the students.
- 00:41
When we go to place the first student, we have 6 to choose from.
- 00:45
Then, for our next slot, there are only 5 left.
- 00:47
With each successive space, there is one less
- 00:50
choice, since another was used up in the previous slot.
- 00:54
Now, to find the possible permutations of students, we simply multiply the number of
- 00:58
choices for all slots together.
- 01:01
Which equals 720, that's 6 factorial.
- 01:04
So we get 720 possible outcomes. Our answer is just (C).
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