If rupee one produces rupees nine over a period of 40 years…

If rupee one produces rupees nine over a period of 40 years, find the rate of simple interest?

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 #63