In What proportion must flour at …0.9 per pound so that the…

In What proportion must flour at $0.8 per pound be mixed with flour at $0.9 per pound so that the mixture costs $0.865 per pound?

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 #45134