I have a question. The question is:

You are buying 5 postcards from a shop that has 4 different postcards.

1) In how many combinations can you buy 5 cards?

2) How many possible combinations do 2 of the 4 different cards contain?

My answers:

1) $\displaystyle \left(^{5}\mathcal{C}_4\right)=\frac{5!}{(4!)(5-4)!}= 5$

2) $\displaystyle \left(^{4}\mathcal{C}_2\right)=\frac{4!}{(2!)(4-2)!}=$ 6

Did I do it right or?

Note: These are without repetitions only.