In what time a sum of money double itself at 4% per…

In what time a sum of money double itself at 4% per annum 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 #39136