need help with this stat question please

Question

"Mary has 25 products in her store. She wants to select 8 products to arrange in the store window. how many different combinations of products can Mary select?"

I got 9.12 x 10²³.

Does that seem correct?

Answer 1

25C8 = 25!/8!(25-8)! = 25!/8!17!

= 25(24)(23)(22)(21)(20)(19)(18)/8(7)(6)(5)(4)(3)(2)

= about 1.086 x 10^6

unless order matters, then you want 25P8 which is much larger =

25!/17!

= about 4.361 x 10^10

but the problem as given uses the word "combinations"

some small calculators have nCr and nPr keys which calculate the combinations and permutations for you

in this example n=25, r = 8

your solution is even larger than 25P17