A fruit seller had some oranges

A fruit seller had some oranges. He sells 40% oranges and still has 300 oranges. How many oranges he had originally?

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 #9214