In a certain boys camp, 20% of the total boys are from…

In a certain boys camp, 20% of the total boys are from school A and 30% of those study science. If there are 21 boys in the camp that are from school A but do not study science then what is the total number of boys in the camp?

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 #8478