below the basic question of permutation:

given that 4 letters are chosen from the wordPAYMENT,find the number of arrangement that start with a vowel

ans: 2P1 x 6P3 = 240

my ans: 120

any guide?(Punch)

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- Jul 23rd 2010, 10:19 PMnikkpermutation - basic
below the basic question of permutation:

given that 4 letters are chosen from the word*PAYMENT*,find the number of arrangement that start with a vowel

ans: 2P1 x 6P3 = 240

my ans: 120

any guide?(Punch) - Jul 23rd 2010, 10:31 PMpickslides
It seems like the question assumes the only vowel can be in the first postition.

Giving $\displaystyle ^2P_1 \times ^6P_3 = 240$

As you may realise you start the 4 letter arrangement with a vowel and have another vowel (as there are 2) in positions 2-4. - Jul 23rd 2010, 10:38 PMnikk
tq for your post, but i hope u can commnet my ans attached as below:

http://img839.imageshack.us/img839/7452/99010889.jpg - Jul 23rd 2010, 10:50 PMpickslides
Why can't N or T be in the last postition? I think you are calculating combinations not permutations as you should. Are you aware of the difference?

- Jul 23rd 2010, 10:54 PMnikk
it mean what i am doing is combination?

- Jul 24th 2010, 06:49 AMSoroban
Hello, nikk!

Why do they include $\displaystyle Y$ in these problems?

There is always that controversy: "Is $\displaystyle Y$ a vowel?"

Quote:

Given that 4 letters are chosen from the word*PAYMENT*,

find the number of arrangement that start with a vowel.

If $\displaystyle Y$ is a vowel: .$\displaystyle \;\underbrace{\text{vowel}}_3 \text{ - } \underbrace{\text{any}}_6 \text{ - } \underbrace{\text{any}}_5 \text{ - }\underbrace{\text{any}}_4 \;=\;360$

If $\displaystyle Y$ isa vowel: .$\displaystyle \;\underbrace{\text{vowel}}_2 \text{ - } \underbrace{\text{any}}_6 \text{ - } \underbrace{\text{any}}_5 \text{ - }\underbrace{\text{any}}_4 \;=\;240$*not*

- Jul 25th 2010, 07:54 AMnikk
tq ror your idea..nice