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Probability and Permutations Help watch

1. Attachment 728082

For part2: the method to solve it would be 6! x 7P4.
But I don't understand how you get 7P4??
2. What is 7P4?
3. 7!/(7-4)!
4. (Original post by zattyzatzat)

For part2: the method to solve it would be 6! x 7P4.
But I don't understand how you get 7P4??
5. (Original post by Y11_Maths)
What is 7P4?
The P is permutation and you'll see a button on your calculator for it.

is the total number of ways you can choose 4 objects from a set of 7 if order matters i.e. ABCD is different to ACBD.

At GCSE you would do 7 x 6 x 5 x 4 which gives you 820 so
6. (Original post by Notnek)
The P is permutation and you'll see a button on your calculator for it.

is the total number of ways you can choose 4 objects from a set of 7 if order matters i.e. ABCD is different to ACBD.

At GCSE you would do 7 x 6 x 5 x 4 which gives you 820 so
Is this GCSE work or A level?
7. (Original post by Y11_Maths)
Is this GCSE work or A level?
Knowing the permutations symbol is A Level but for GCSE you might be asked a question like

How many four letter words can be made from the letters STUDENT where each letter is different.

There are 7 choices for the first letter, 6 for the second etc. so the answer would be 7 x 6 x 5 x 4 = 840.
8. (Original post by Notnek)
Knowing the permutations symbol is A Level but for GCSE you might be asked a question like

How many four letter words can be made from the letters STUDENT.

There are 7 choices for the first letter, 6 for the second etc. so the answer would be 7 x 6 x 5 x 4 = 840.
Yeah I understand this thanks

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