The tax on a commodity is diminished by 40% but its consumption…

The tax on a commodity is diminished by 40% but its consumption is increased by 25%. Find the decrease percent in the revenue derived from it?

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 #7596