Ten different letters of an alphabet are given

MATHEMATICS · Single correct · CBSE · Mathematics · Permutations and Combinations · Permutations and Combinations

Problem

Ten different letters of an alphabet are given. Words with five letters are formed with these given letters. Then the number of words which have atleast one letter repeated is : (a) 30240 (b) 69760 (c) 69780 (d) 99784

Related theory

Permutations
Counting Techniques
Counting principle and permutations
Algebra
Fundamental principle of counting
Permutations and Combinations

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