How many words can be formed out of the letters of the word ‘ORIENTAL’ so that the vowels always occupy the odd places?
To find: number of words formed
Condition: vowels occupy odd places
There are 8 letters in the word ORIENTAL and vowels are 4 which are O, I, E,A respectively.
There is 4 odd places in which 4 vowels are to be arranged.
The rest 4 letters can be arranged in 4! Ways.
Formula:
Number of permutations of n distinct objects among r different places, where repetition is not allowed, is
P(n,r) = n!/(n-r)!
Therefore, the total arrangement is
P(4,4) × 4! = × 4! =
×4! =
× 24 = 576.
Therefore, total number of words formed are 576.