|
Permutation and Combination
January 07, 2004
In how many ways can the letters of the word “PROBLEM” be rearranged to make 7 letter words such that none of the letters repeat?
| (1) | 7! |
| (2) | 7C7 |
| (3) | 77 |
| (4) | 49 |
| (5) | None of these |
Correct Answer Choice (1)
Solution:
There are seven positions to be filled.
The first position can be filled using any of the 7 letters contained in PROBLEM.
The second position can be filled by the remaining 6 letters as the letters should not repeat.
The third position can be filled by the remaining 5 letters only and so on.
Therefore, the total number of ways of rearranging the 7 letter word = 7*6*5*4*3*2*1 = 7! Ways.
| 
