If books bought at prices ranging from Rs

If books bought at prices ranging from Rs. 90 to Rs. 190 are sold at prices ranging from Rs. 120 to Rs 260, what is the greatest possible profit that might be made in selling 21 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 #67085