Given word is
CHILD.
Finding the number of
5 lettered words is similar to number of ways of filling
5 vacant places by
5 letters as shown:
So, first vacant place can be filled in
5 different ways by any one of the letters
C, H, I, L, D.
Since, the repetition of letters is not allowed. Which means no letter can be used more than once.
∴ Second vacant place can be filled by any of the remaining
4 letters in
4 different ways.
Similarly, third, fourth and fifth vacant place can be filled in
3,2 and
1 different ways respectively.
Now, by fundamental counting principle the required number of ways is
5×4×3×2×1.
Hence, required number of words formed from word
CHILD is
=5×4×3×2×1=120.