Subject: General Aptitude · Chapter: Permutations and Combinations · Exam: · Marks: · Difficulty:
In how many different ways can the letters of the word BANKING be arranged in such a way that the vowels always come together? (Bank P.O., 2009)
(a)120
(b)240
(c)360
(d)540
(e)720
Answer
Answer (as printed): E
Explanation
The given word contains 7 letters of which N is taken 2 times. We keep the vowels (AI) together and treat them as 1 letter. Thus, we have to arrange 6 letters BNKNG(AI) of which N occurs 2 times and the rest are different. 6 These can be arranged in = (6 × 5 × 4 × 3) = 360 ways. 2 Now 2 vowels (AI) can be arranged among themselves in 2 ways. ∴ Required number of ways = (360 × 2) = 720.
Explanation as extracted from the printed page; notation may be imperfect.