In how many ways can letters in a word CALCULUS be rearranged such that no 2 same letters stand next to each other. I’ve been thinking of Inclusion-Exclusion principle. Is there any different way to solve this task?

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    $\begingroup$ Inclusion-Exclusion should work fine. You have three letters which appear twice, so you will not get that many terms in the final expansion for the rearrangements. $\endgroup$ – EuxhenH Jan 7 at 10:28
  • $\begingroup$ I know but I wonder if there’s any other way to do that not using sophisticated methods $\endgroup$ – Michael Jan 7 at 11:26
  • $\begingroup$ Not using sophisticated methods would force you to do tedious casework. $\endgroup$ – N. F. Taussig Jan 7 at 16:02
  • $\begingroup$ What would be the final answer then $\endgroup$ – Michael Jan 8 at 8:52
  • $\begingroup$ If you want additional feedback, then you should edit your post to show what you have attempted and explain where you are stuck. This tutorial explains how to typeset mathematics on this site. $\endgroup$ – N. F. Taussig Jan 8 at 10:56

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