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# How many 3-letters words can be formed using a, b, c, d, e if

Question:

How many 3-letters words can be formed using a, b, c, d, e if

(i) Repetition of letters is not allowed?

(ii) Repetition of letters is allowed

Solution:

(i) if repetition of letters is not allowed then number of many 3 -letters words that can be formed using $a, b, c, d, e$ are

$5 \times 4 \times 3=60$

(ii) if repetition of letters is allowed then number of many 3-letters words that can be formed using $a, b, c, d$, e are

$5 \times 5 \times 5=125$