basically the question means
how many ways are there to choose 4 classes if you have 200 classes to choose from?
so permutations (combinations is if you can repeat choices, but obviously you won't take the same class 4 times)
slot system (simple way to explain permutations)
so you have 4 slots to fill and you have 200 choices
1st slot: 200 choies
2nd slot: 199 choices (1 less choice)
3rd slot: 198 choices (1 less choice)
4th slot: 197 choices (1 less choice)
to find how many ways, we do,
200*199*198*197= 1,552,438,800 choices
no it is not 200/4
