This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
We are looking for the base so the formula for the base is:
Base= \frac{Percentage}{Rate} = \frac{25}{0.1} =250

We converted 10% to a decimal which is 0.1. A rate is the number with the percentage sign (%). A base is the number which usually has the keyword "of" before it.