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FrozenWasteland · 61-69, M
12.
Here's a way of looking at it with very little math.
There are 5! ways of arranging 5 things. 5 * 4 * 3 * 2 * 1 = 120. Of those, one fifth have B on the left so, there are 120 / 5 = 24 possibilities to consider further.
Of these 24 arrangements of A, C, D and E, there are going to be 24 / 4 = 6 arrangements with each letter on the right. Since either C or D on the right satisfies the requirement and there are 6 of each, there are 12 arrangements in total that satisfy the requirements.
Here's a way of looking at it with very little math.
There are 5! ways of arranging 5 things. 5 * 4 * 3 * 2 * 1 = 120. Of those, one fifth have B on the left so, there are 120 / 5 = 24 possibilities to consider further.
Of these 24 arrangements of A, C, D and E, there are going to be 24 / 4 = 6 arrangements with each letter on the right. Since either C or D on the right satisfies the requirement and there are 6 of each, there are 12 arrangements in total that satisfy the requirements.
I’m no expert but biscotti arranged in a line! 🥺
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JoePourMan · 61-69, M
6
1 & 5 are constant
2 3 4
2 4 3
3 2 4
3 4 2
4 2 3
4 3 2
1 & 5 are constant
2 3 4
2 4 3
3 2 4
3 4 2
4 2 3
4 3 2
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helenS · 36-40, F
@JoePourMan Maybe I'm wrong? I thought I have three positions in the middle, and the permutation of three in three is 6, and I have two possibilities for the last position, so 6*2=12.
@JoePourMan there are 2 options for the 5th position
JoePourMan · 61-69, M
@SooperSarah then the question was asked wrong. Either one or the other has to be on the end implies a fixed end position
54
I have no idea lol
I have no idea lol
@Riemann I didn't figure in they couldn't be repeated. So it's 1x3x2x2x1
Riemann · 31-35, M
@SooperSarah Could you please explain ma'am?
@Riemann you have one option for the first spot, three for the second, two for the third, two for the fourth, which leaves one for the fifth.
helenS · 36-40, F
12?
littlepuppywantanewlife · 31-35, M
ABCDE are friends but you want them to be BACED
Riemann · 31-35, M
Just give me the butter!