A sum of money at simple interest amounts to Rs

A sum of money at simple interest amounts to Rs. 825 in 3 years and to Rs. 830 in 4 years. The sum is?

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 #18662