The combustion of a sample butane, C4H10 (lighter fluid) produced 2.46 grams of water. how much oxygen was used up in grams

The balanced combustion reaction for butane is;

2C4H10 + 13O2 → 8CO2 + 10H2O

Molar mass of water = 18.02 g/mol

Molar mass of oxygen = 32 g/mol

2.46g H2O (1 mol H2O/18.02g) (13 mol O2/10 mol H2O) (32g O2/1 mol O2) = 5.68g O2