In how many ways can the letters of the word 'permute' be arranged if: a) the first and last places are occupied by consonants? b) the vowels and consonants occupy alternate places?
CVCVCVC--- this is the way letters should be arranged VCVCVCV--- there are only 3 vowels; so this order does not maintain vowel-constant in alternatre position. 3 vowels can be arranged in 3!/2! way (there are 2 E) = 3 4 constant in 4! way = 24
so how do you work out part a?
The first place needs a consonant. So 4 possibilities. The last place needs a consonant. So 3 possibilities. For the middle, 5! possibilities. I get 120 x 12 = 2400.
the answer is 720 ways
The first place needs a consonant. So 4 possibilities. The last place needs a consonant. So 3 possibilities. For the middle, 5! possibilities. (since 2 e's , divide 2!) you get (4*3) * 5!/2!
Forgot the duplicates. You are right.
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