After a storm deposits 120 billion gallons of water into the city…

After a storm deposits 120 billion gallons of water into the city reservoir, the reservoir is 85% full. If the original contents of the reservoir totaled 220 billion gallons, the reservoir was approximately what percentage full before the storm?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #26704