Aptitude - Permutation and Combination - Discussion
Discussion Forum : Permutation and Combination - General Questions (Q.No. 12)
12.
How many 4-letter words with or without meaning, can be formed out of the letters of the word, 'LOGARITHMS', if repetition of letters is not allowed?
Answer: Option
Explanation:
'LOGARITHMS' contains 10 different letters.
| Required number of words | = Number of arrangements of 10 letters, taking 4 at a time. |
| = 10P4 | |
| = (10 x 9 x 8 x 7) | |
| = 5040. |
Discussion:
68 comments Page 5 of 7.
Arurag said:
9 years ago
The answer is correct. This is a permutation.
i.e npr=n!/(n-r)! Here n! is 10, r is 4.
i.e npr=n!/(n-r)! Here n! is 10, r is 4.
Sanjana said:
10 years ago
Can the clear explanation of this problem can be given by someone? Since I dint get it.
Hyndavi said:
9 years ago
They mentioned that no repetition are allowed then how could we use permutations here?
Hansh said:
1 decade ago
Why you have used permutation here? please tell me the repetions of 4 letters concept?
Mijanul said:
6 years ago
nCr = ( 1 / r! ) * nPr.
nPr = r! * nCr.
That's why here nPr (permutation) is used.
nPr = r! * nCr.
That's why here nPr (permutation) is used.
(1)
Akash said:
1 decade ago
What does the exclamation mark imply? please can someone explain this question?
(1)
Shezy said:
1 decade ago
So it means when repetitions not allowed it is an ordering condition ! ?
(1)
Sann said:
1 decade ago
How can I identify the given question from permutation or combination?
(1)
Olamide said:
9 years ago
If repetition is allowed then it would be 10 * 10 * 10 * 10 = 10000.
Krishan said:
1 decade ago
I dint get it why we are using permutation here? can you explain.
(1)
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