SOLUTION: How many distinguishable words can be formed from the letters of the word "casserole" if each letter is used exactly once? If I told you the answer is 90,720; explain in your own

Question 430122: How many distinguishable words can be formed from the letters of the word "casserole" if each letter is used exactly once? If I told you the answer is 90,720; explain in your own words using complete sentences which formula you used and why (Permutations or Combinations), and how you solved the problem. When you state your answer here, please also tell us when the use of combinations is appropriate compared to when the use of permutations.
Found 2 solutions by sudhanshu_kmr, richard1234:
Answer by sudhanshu_kmr(1152) (Show Source):
You can put this solution on YOUR website!

no. of possible words = 9!/ [ 2!*2!]
=90720
here letter 's' and 'e' are 2 times, others are only one times.
so divide by 2! * 2! = 4
it is permutation because it is related to arrangement.

for further help, u r welcome to contact me ....

Answer by richard1234(5390) (Show Source):
You can put this solution on YOUR website!
Casserole is 9 letters

9P9/(2!2!) = 9!/(2!2!) = 90720, the number of total ways. I used permutations because the order matters. In general, try to use permutations where order matters, and combinations where the order doesn't matter.