A fruit seller had some apples

A fruit seller had some apples. He sells 40% apples and still has 420 apples. Originally, he had:

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 #1619