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Question
How many words can be formed with the letters of the word 'PARALLEL' so that all L's do not come together?
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Solution
The word PARALLEL consists of 8 letters that include two As and three Ls.
Total number of words that can be formed using the letters of the word PARALLEL =\[\frac{8!}{2!3!}\] = 3360
Number of words in which all the Ls come together is equal to the condition if all three Ls are considered as a single entity.
So, we are left with total 6 letters that can be arranged in\[\frac{6!}{2!}\] ways (divided by 2! since there are two As), which is equal to 360.Number of words in which all Ls do not come together = Total number of words\[-\] Number of words in which all the Ls come together = 3360\[-\]360= 3000
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