I have a question about percentage. If
$0$ represents $10\%$
$15$ represents $100\%$
$30$ represents $200\%$
What does $25$ represent in percent value?
I have obtained that $25$ represents $166\%$
Updated:
this is a hypothetical situation. for example if you are a student and you have to pass an exam. If you go to exam and you do not anything ($0$ tasks) you will achieve $10\%$. If you go to exam and solve $15$ tasks you will achieve $100\%$ and if you solve $30$ tasks you will achieve $200\%$. I think we can supose that $0\%$ is realized when you do not participate to exam (you are absent)
Interpolating linearly between the points $(15,100)$ and $(30,200)$ indeed gives $(25,166\frac{2}{3})$.
However, there is an infinite number of functions going through the points $(0,10)$, $(15,100)$ and $(30,200)$, so you might want to clarify what represents means in your question :)