(i) How many different words can be formed with letters of the word ‘SUNDAY’ ? (ii)How many of the words begin with N? (iii)How many begin with N and end Y?

Explanation

Given as


The word 'SUNDAY'


The total number of letters in the word 'SUNDAY' is `6 .`


Therefore, number of arrangements of 6 things, taken all at a time is `{P}_{6}` `=6 !=6 times 5 times 4 times 3 times 2 times 1=720`


Then, we shall find the number of words starting with `N`


Therefore let's fix the first position with letter N, now remaining number of letters is `5 .`



Number of arrangements of 5 things, taken all at a time is `{P}_{5}=5` ! `=5 times 4 times 3 times 2 times 1` `=120`


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