If books bought at prices ranging from Rs

If books bought at prices ranging from Rs. 130 to Rs. 320 are sold at prices ranging from Rs. 210 to Rs 310, what is the greatest possible profit that might be made in selling 18 books ?

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 #44145