Boy sells a book for Rs.450 he gets a loss of 10%…

Boy sells a book for Rs.450 he gets a loss of 10%, find CP of the book?

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 #67953