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?
40
400
5040
2520
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.

Shivam said:   1 decade ago
I'm confused for in which question we do permutation and combination. I have used combination in this question but I was wrong. But some other questions which as same as this question solved by combination. Why did you use permutation on this?

Shashwat said:   1 decade ago
Why permutation is used explain?

Yazhini said:   1 decade ago
! implies that it is a multiplication sign up to 1. It is neither a permutation nor a combination. For ex 4! implies that 4*3*2*1=24. is it clear guy?

Akash said:   1 decade ago
What does the exclamation mark imply? please can someone explain this question?
(1)

Satish said:   1 decade ago
Please tell me that when we should use permutations and when we should combinations with an example?

Vimal said:   1 decade ago
I am not clear with this. They gave a condition that repetition is not allowed. when we use 10p4, (i.e. is permutation) it satisfy the given condition?

Chandani said:   1 decade ago
When we form LOGA and AGOL it is permutation but in combination we don't write like r, s is similar to s, r -in combination, not in permutation. So in above question we are not allowed to double the letter but are allowed to use the same letter in different words. .

AISH said:   1 decade ago
If position of word matter (no repetition allowed) Then we have to use permutation.

And if no position matter we have to use combination.

Sann said:   1 decade ago
How can I identify the given question from permutation or combination?
(1)

Kuldeep vijay said:   1 decade ago
Yes, when repetitions not allowed it is an ordering condition.


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