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In How Many Ways Can the Letters of the Word 'Arrange' Be Arranged So that the Two R'S Are Never Together? - Mathematics

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प्रश्न

In how many ways can the letters of the word 'ARRANGE' be arranged so that the two R's are never together?

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उत्तर

The word ARRANGE consists of 7 letters including two Rs and two As, which can be arranged in\[\frac{7!}{2!2!}\]ways.

∴ Total number of words that can be formed using the letters of the word ARRANGE = 1260
Number of words in which the two Rs are always together = Considering both Rs as a single entity
 = Arrangements of  6 things of which two are same (two As)

=\[\frac{6!}{2!}\]

= 360

Number of words in which the two Rs are never together = Total number of words- Number of words in which the two Rs are always together

= 1260 - 360= 900
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Factorial N (N!) Permutations and Combinations
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 16: Permutations - Exercise 16.5 [पृष्ठ ४३]

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आरडी शर्मा Mathematics [English] Class 11
अध्याय 16 Permutations
Exercise 16.5 | Q 10 | पृष्ठ ४३

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