The amount in gr mass of solute present in 100 g mass of solution is called concentration. If 50 g of salt in 200 g of water, the concentration, of that solution would be

Concentration of a solution is expressed in different methods. One of the method is mass percentage

Mass percentage,$\left(\mathrm{w}/\mathrm{W}\%\right)=\frac{\mathrm{Mass}\hspace{0.17em}\mathrm{of}\hspace{0.17em}\mathrm{solute}}{\mathrm{Mass}\hspace{0.17em}\mathrm{of}\hspace{0.17em}\mathrm{solution}}\times 100$

$\mathrm{W}\%=\left(\frac{\mathrm{W}}{\mathrm{w}+\mathrm{W}}\right)\times 100$

         $=\left(\frac{50}{50+200}\right)\times 100=\frac{50}{200}\times 100$

$\therefore \left(\mathrm{w}/\mathrm{W}\right)\%=20\%$