A man sold 20 articles for …50 to incur a loss 20%

A man sold 20 articles for $60 and gained 20%. How many articles should he sell for $50 to incur a loss 20%?

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 #51