Q. Find the number of arrangements of the letters of the word INDEPENDENCE when all the vowels always occur together.
Permutations and Combinations
Solution:
Solution:
for the time being. This single object together with $7$ remaining objects will account for $8$ objects. These $8$ objects, in which there are $3 N s$ and $2\,\,\, Ds$, can be rearranged in $\frac{8!}{3! 2!}$ ways. Corresponding to each of these arrangements, the $5$ vowels $E, E, E, E$ and $I$ can be rearranged in $\frac {5!}{4!}$ ways .Therefore, by multiplication principle, the required number of arrangements $= \frac{8!}{3! 2!} \times \frac{5!}{4!} = 16800$