The salary of a person was reduced by 20%

The salary of a person was reduced by 20%. By what percent should his reduced salary be raised so as to bring it at par with his original salary?

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 #21830