The number of possible combinations can be calculated by formula [tex]C_n^k= \frac{n!}{k!(n-k)!} [/tex].
There are eight different concert dates that Jen could attend, then n=8.
Jen can only afford to see three shows, then k=3
and
[tex]C_8^3= \frac{8!}{3!(8-3)!}=\frac{1\cdot 2\cdot 3\cdot 4\cdot5 \cdot 6\cdot 7\cdot 8}{1\cdot 2\cdot 3\cdot 1 \cdot 2 \cdot 3 \cdot 4 \cdot 5} =56[/tex]
Answer: 56 possible combinations.
