A watch was sold at a loss of 15%

A watch was sold at a loss of 15%. If it was sold for Rs.400 more, there would have been a gain of 5%. What is the cost price?

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 #46141