Answer:
30%
Explanation:
Chemical concentrations are general defined as the ratio between amount of solute (Less amount compound, hydrogen peroxide) and amount of solvent or solution (More amount, water).
For example, volume/volume percentage -(V/V%)- is defined as 100 times the ratio between volume of solute (90mL of hydrogen peroxide) and volume of solution (300mL of solution), that is:
V/V% = 90mL / 300mL * 100 =
30%
