The average (arithmetic mean) monthly income of four workers is …2,250

The average (arithmetic mean) monthly income of four workers is $2,000. After one worker’s income increases by 25 percent the new average income is $2,250. What was the original income of the worker whose monthly income increased?

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 #13522