[tex]Dane:\\m_{r} = 200 \ g\\C_{p} = 20\%\\Szukane:\\m_{s} = ?[/tex]
[tex]Obliczenia[/tex]
[tex]C_{p} = \frac{m_{s}\cdot100\%}{m_{r}} \ \ \rightarrow \ \ m_{s} = \frac{C_{p}\cdot m_{r}}{100\%}\\\\m_s = \frac{20\%\cdot 200 \ g}{100\%}\\\\\boxed{m_{s} = 40 \ g}[/tex]
