She can arrange the 9 paintings in 362,880 different ways, and she can select 126 different combinations of 4.
And so on for the rest of the positions.
The total number of different combinations is equal to the product between the numbers of options:
C = 9*8*7*6*5*4*3*2*1 = 9! = 362,880
b) This will be given by the combinations of 4 out of 9, or:
C(9, 4), where:
[tex]C(9, 4) = \frac{9!}{(9 - 4)!*4!} = \frac{9*8*7*6}{4*3*2*1} = 126[/tex]
She can select 126 different combinations of 4 paintings.
If you want to learn about combinations:
https://brainly.com/question/11732255
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