how many ways can the letters of the following words be arranged?
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word combination....
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For 5-letter words you need to calculate=5*4*3*2*1=120
Because you have 5 spots for the 1st letter, then 4 spots for the second letter, etc.
For 4-letter words you need to calculate=4*3*2*1=24
The same logic applies as the one stated above.
And use the same logic for 6-letter words.
Because you have 5 spots for the 1st letter, then 4 spots for the second letter, etc.
For 4-letter words you need to calculate=4*3*2*1=24
The same logic applies as the one stated above.
And use the same logic for 6-letter words.
The more you look, the more you see.
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Don't forget that you also need to divide by n!, where "n" is the number of times a letter repeats itself in the word. So, for example, SCHOOL would be:
6! / 2!
Since there are two "O"s.
So, if we had a word such as "ASSESS", that would be:
6! / 4!
Since the "S" repeats itself four times.
It gets even weirder if you have multiple letters that repeat, such as RECESS - both the "E" and the "S" repeat twice. So, we would have:
6! / (2!*2!)
I can't say I've ever seen one of these on the real GMAT, but it's handy to know.
6! / 2!
Since there are two "O"s.
So, if we had a word such as "ASSESS", that would be:
6! / 4!
Since the "S" repeats itself four times.
It gets even weirder if you have multiple letters that repeat, such as RECESS - both the "E" and the "S" repeat twice. So, we would have:
6! / (2!*2!)
I can't say I've ever seen one of these on the real GMAT, but it's handy to know.
Jim S. | GMAT Instructor | Veritas Prep