Question 681934: we want to form a 4 letter password using letters from A,B,C,D,E,F without repetition, what is the probability that the first letter of the password is A and the last letter is F??
Answer by MathLover1(20849)   (Show Source):
You can put this solution on YOUR website! 4 letter password using letters from A,B,C,D,E,F
By assuming that the first letter is "A", and the last letter is “F",
Therefore, one has to find two more letters from the remaining 4 letters.
Of the 4 letters, there are 1 B, 1 C, 1 D, and 1 E .
The second and third positions can have two different letters.
When the two letters are different. One has to choose two different letters from the 4 available different choices. This can be done in 4 * 3=12 ways.
Total number of possibilities is 12.
1. A,B,C,F
2. A,C,B,F
3. A,B,D,F
4. A,D,B,F
5. A,C,D,F
6. A,D,C,F
7. A,C,E,F
8. A,E,C,F
9. A,D,E,F
10. A,E,D,F
11. A,B,E,F
12. A,E,B,F
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