##### Find the number of permutations of the first eight letters of the alphabet taking five letters at a

label Algebra
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Time. A.1680 B.56 C.6720 D.109

Jun 11th, 2015

Since order does matter (this is because the word "cab" is different than "abc"), we can use the permutation formula

Plug in  (this is number of letters given) and  (this is the number of letters we can use together at a time)

Subtract  to get 5

Expand 8!

Expand 5!

Cancel

Simplify

Now multiply 8*7*6 to get 336

So 8 choose 3 (where order does matter) yields 336 unique combinations

Jun 11th, 2015

sorry i did for 3 instead of 5....let me do it now!

Jun 11th, 2015

6,720..........................................................

Jun 11th, 2015

Thank you so much for explaining!

Jun 11th, 2015

welcome dear!

Jun 11th, 2015

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Jun 11th, 2015
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Jun 11th, 2015
Oct 20th, 2017
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