The number of four-letter words that can be f | vedclass

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Question

(b)

Out of given three letters $a, b, c$, we will repeat exactly one of the letter and we can do this in ${ }^3 C_1$ ways.

Now, we have four let

Vedclass · Accepted Answer

$36$

Vedclass · Answer

(b)

Out of given three letters $a, b, c$, we will repeat exactly one of the letter and we can do this in ${ }^3 C_1$ ways.

Now, we have four letters and out of these four letters two are identical, so number of ways to arrange these four letters is $\frac{4 !}{2 !}$.

So, the number of four letter words that can be formed with letters $a, b, c$ such that all three letters occur is

${ }^3 C_1 	imes \frac{4 !}{2 !}=36$

The number of four-letter words that can be formed with letters $a, b, c$ such that all three letters occur is

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