How many different ways could you choose three pants to pack for a weekend trip, if you have 12 pants to choose from? Assume the pants are selected without replacement.

Question

a. 12! / 3!
b. 12! / 9!
c. 12! / 8!⋅4!
c. 12! / 9!⋅3!

If the expected value of an extended warranty sold by an electronics store is $21, what does that mean?
a. by the customer.
b. The store makes $21 in revenue each time they sell this warranty.
c. If store sells this same warranty many, many times, they will make (on average) $21 in revenue for each warranty sold.
d. If a customer purchases this warranty and their item breaks, the store will lose $21 when they replace the item.

Answer 1

The key word is "choose" so the order does not matter
you are choosing 3 of 12 which is
C(12,3) = by definition 12!/(3!9!)

btw, those brackets are necessary when typing it like that
the correct choice of c) should have those brackets

Answer 2

Can you explain the second question? I believe it might be b or c