Amon & Rhonda combined have 215 marbles. If Amon owns 55 marbles more than Rhonda, how many marbles does Rhonda have? Let's think first. Chain of thought:
Let's say Rhonda has m marbles. The total number of marbles that Ammon has is m + 55. Amon & Rhonda combined have m + (m + 55) = 215. This means the total number of marbles they have together is 2m + 55 = 215. 2m = 215 - 55. The total number of marbles that Rhonda has is m = 160 / 2. Rhonda has m = 80 marbles.
Therefore, the answer is 80.