Subject: General Aptitude · Chapter: Permutations and Combinations · Exam: · Marks: · Difficulty:
In how many different ways can the letters of the word OPTICAL be arranged in such a way that the vowels always come together?
(a)120
(b)720
(c)2160
(d)4320
(e)None of these
Answer
Answer (as printed): B
Explanation
The given word contains 7 different letters. We keep the vowels (OIA) together and treat them as 1 letter. Thus, we have to arrange the letters PTCL(OIA). These can be arranged in 5 = 120 ways. The vowels (OIA) can be arranged among themselves in 3 = 6 ways. ∴ Required number of ways = (120 × 6) = 720.
Explanation as extracted from the printed page; notation may be imperfect.