A fruit seller had some apples

A fruit seller had some apples. He sells 40% apples and still he has 420. Originally he had how many apples?

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 #6984