Aptitude - Permutation and Combination - Discussion

Discussion Forum : Permutation and Combination - General Questions (Q.No. 14)
14.
In how many different ways can the letters of the word 'OPTICAL' be arranged so that the vowels always come together?
120
720
4320
2160
None of these
Answer: Option
Explanation:

The word 'OPTICAL' contains 7 different letters.

When the vowels OIA are always together, they can be supposed to form one letter.

Then, we have to arrange the letters PTCL (OIA).

Now, 5 letters can be arranged in 5! = 120 ways.

The vowels (OIA) can be arranged among themselves in 3! = 6 ways.

Required number of ways = (120 x 6) = 720.

Discussion:
36 comments Page 4 of 4.

Gaurav said:   7 years ago
Short trick of that question is;

Total letters=7!,
Total vowels=3!(or 1group),
7!-3!=4!,
4!+1!(group of vowel)=5!,
Num of ways=5!*3!=720 is the answer.

Karan kumar said:   7 years ago
Vowels come together so there are 5!
And 3!.
120 * 6 = 720.

Pudi sai kumar said:   7 years ago
Different ways of arranging the word "EASYQUIZ" where vowels always come together.

Can anyone solve this clearly?
(1)

Rajeev said:   6 years ago
But the vowel can come in the beginning like;

OIAPTCL.
PTCLOIA.
So, we should add like this (5!*3!+5!*3!)
(1)

Ayesha said:   6 years ago
OAI are 3 vowels should be considered as one letter (OAI) and the 3 vowels among themselves can be arranged in 3! ways ie.,6ways.

Now the remains consonants are PCTL are 4 letters plus we should consider the 3 vowels as one letter (4+1)=5! ways {5!=120}.

The required no.of ways = 120 * 6 =720 ways.
(3)

Justice said:   3 years ago
Can you solve this "in how many different ways can the letters of the word "OPTICAL" be arranged.

So that O&A can always be together.
(1)


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