How many words can be formed from the letters of the word 'SERIES' which start with S and end with S?
Question:
How many words can be formed from the letters of the word 'SERIES' which start with S and end with S?
Solution:
The word SERIES consists of 6 letters including two Ss and two Es.
The first and the last letters are fixed as S.
Now, the remaining four letters can be arranged in $\frac{4 !}{2 !}$ ways $=12$