There is no relation. What should the Peroxide do. Oxidizing of the sugar? If yes then you need a balanced redox reaction equation. If not then it doesn't matter you can add how much you like.
Or do you want the mixture 1:20 mole.
Convert 8 g sugar to mole. Then multiply this with 20 and calculate back the mass of peroxide.
This is 100% , calculate to 30% and then calculate volume by using the specific gravity.