Counting, Combinations Stuck here :( What's the number of ways a person can score 60 total points from taking 4 tests given that 3 of 4 tests each have maximum score of 50 points and other test a maximum score of 100 points?
My strategy is to enumerate all ways in which scores from each exam sum up to 60 points. Is there some efficient way to do this? 

(I'm assuming only non-negative integer values for scores, doesn't matter how you get the scores, and the three 50-max tests are distinguishable.)
Hint: This problem reduces [how?] to the somewhat easier case of finding the number of ways a person can score $k$ points on three tests which have a maximum score of $50$, for arbitrary $0\leq k\leq 60$.
For the reduced problem, imagine you have $k$ points and are trying to distribute them among the tests. This is the same as choosing how to break a row of $k$ blocks into three pieces. If you've not seen problems like this before, you might get some intuition by drawing some pictures for these broken rows for medium values of $k$, or enumerating all of them for tiny values of $k$.
