When there is no repetition of the letters, the number of permutations (order counts) is nPr, taking r letters at a time n!/(n-r)!.
If all n letters are taken (as in the present case) to make the word, nPn reduces to
n!/(n-n)!=n!/0!=n!/1 = n!
However, if there are repetitions of letters, we have to reduce the number of permutations by the factor r1! for each occurrence of the duplication/repetition.
1. How many arrangements of the six letters of the word "number" are there?
6 letters, no repetitions, 6P6=6!=720.
2. How many arrangements of the eleven letters of the word "mathematics" are there?
We note repetitions of the letters m(2), a(2), t(2), so the number of arrangements
The number of arrangements of five letters from the word 'magnetic' that contain the word net is: a)60 b)100 c)360 d)630 e)720 we're still doing this at school and I still don't get it; since I have to use three of the eight
A license plate is to consist of two letters followed by three digits. How many different license plates are possible if the first letter must be a vowel, and repetition of letters is not permitted, but repetition of digits is
How many arrangements are possible using the letters in the word FUZZY if each letter "Z" is distinctly different than the other? How many arrangements are possible if the letter "Z" is interchangeabe with the other? Explain your
sorry, I know I already asked this, but I called some of my friends and it seems I copied down the homework wrong. The question is the number of arrangements of five letters from the word 'magnetic' that end in a vowel is: A 360 B