A shopkeeper purchased 90 kg of potatoes for Rs

A shopkeeper purchased 90 kg of potatoes for Rs. 540 and sold the whole lot at the rate of Rs. 8 per kg. What will be his gain percent?

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 #6600