Question -
Answer -
Given:
The word ‘SERIES’
There are 6 letters inthe word ‘SERIES’ out of which 2 are S’s, 2 are E’s and the rest all aredistinct.
Now, Let us fix 5letters at the extreme left and also at the right end. So we are left with 4letters of which 2 are E’s.
These 4 letters can bearranged in n!/ (p! × q! × r!) = 4! / 2! Ways.
Required number ofarrangements is = 4! / 2!
= [4×3×2!] / 2!
= 4 × 3
= 12
Hence, a total numberof arrangements of the letters of the word ‘SERIES’ in such a way that thefirst and last position is always occupied by the letter S is 12.