What you need to do is find the smallest multiple that they both have (i forgot what that is called) list them like this:
12: 24 36 48 60 72
15: 30 45 60 75
60 is the lowest number that they both can multiply to
60 cups/lids is the answer

The vertex is at (0,-5), therefore the range goes from (-infinity, - 5]
Divide 150 by 50 to get 3
The answer is b uh it’s 4 in the morning I hope this helped and I hope you can still answer the question