In a circuit board factory, all circuit boards that pass a verification…

In a circuit board factory, all circuit boards that pass a verification process are certified. Every board that fails the verification process is indeed faulty, but 1/8 of those that pass are also faulty. Approximately how many faulty circuit boards exist in a group of 800 circuit boards where 64 fail inspection?

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 #8416