1.

14 different letters of alphabet are given, words with 6 letters are formed from these given letters. How many number of words are there which have at least one letter repeated?(a) 892742(b) 999988(c) 213216(d) 786730I had been asked this question in semester exam.My question is from Counting in section Counting of Discrete Mathematics

Answer»

Right answer is (b) 999988

Easy explanation: Number of WORDS which have at least one letter REPLACED = total number of words – total number of words in which no letter is REPEATED, => 10^6 – ^12P6 => 1000000 − 924 = 999988.



Discussion

No Comment Found

Related InterviewSolutions