Aptitude - Permutation and Combination - Discussion

Discussion Forum : Permutation and Combination - General Questions (Q.No. 2)
2.
In how many different ways can the letters of the word 'LEADING' be arranged in such a way that the vowels always come together?
360
480
720
5040
None of these
Answer: Option
Explanation:

The word 'LEADING' has 7 different letters.

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

Then, we have to arrange the letters LNDG (EAI).

Now, 5 (4 + 1 = 5) letters can be arranged in 5! = 120 ways.

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

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

Video Explanation: https://youtu.be/WCEF3iW3H2c

Discussion:
97 comments Page 6 of 10.

Shivam said:   7 years ago
Why 120*6 why not 120+6? Please explain me.

Bharti said:   1 decade ago
Thanks a lot. I had confusion before your explanations. Thanks a lot.

Technothelon said:   9 years ago
@Brian.

There aren't such kind of ways. Because arrangement is not taken into consideration when we do combinations.

DragonSlayer said:   8 years ago
Friends in the word LEADING.
there are three vowels A,E,I
With AEI you can form 3! arrangements ie 6 arrangements
As we want the vowels to come together they may be placed at any of the 5 locations on the word LEADING.

So there are 5! arrangements for this.
5! X 3!=720.
The 3 vowels are considered as a single word to simply this process of counting the number if locations.

Heta Vaghasia said:   8 years ago
Answer will be 72. How 720 came?

Sandeep said:   1 decade ago
can any one explain ? y 5!*3! & y not like this 5!+3!

Jhansi sri said:   1 decade ago
Please help me quickly why we take 5!*3!, Why we can't take 5!+3!.

Amnafida said:   1 decade ago
Describe that how we know about here permutation is use?

Amna fida said:   1 decade ago
How we know that factorial will use here?

Taku mambo bellnuisemarbel said:   1 decade ago
Please help me with this; whenever I hear of probability that a variable is being selected what should I think of?


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