Chapter 2 - Equations, Inequalities, and Problem Solving - 2.4 Applications with Percent - 2.4 Exercise Set - Page 109: 49

$2.5$

Typical percentage problem: What percent ($n$, as a decimal number) of (the base amount $y)$ is $x?$ Translated:$\quad n\cdot y=x$ --- Here, reworded, $ 12\%$ of ($y=?$) is ($x=0.3$)$?$ Translated:$\quad 0.12\cdot y=0.3$ ($ 12\%$ converted to decimal notation is $0.12)$ ... divide the last equation with $0.12$ $y=\displaystyle \frac{0.3}{0.12}=2.5$