A trader mixes 10 kg of rice at Rs

A trader mixes 10 kg of rice at Rs. 20 per kg with 20 kg of rice of other variety at Rs.40 per kg and sells the mixture at Rs. 40 per kg. His profit percent is:

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 #980