Really hard chem question (grade 9)?

20 cm (cube) butane added to 150 cm (cube) of oxygen which is in excess and it (mixture) is ignited, what is the volume of unreacted oxygen left and what is the value of CO2 formed? C4H10 + 6.5 O2 =4 CO2 + 5 H20 (volume of oxygen left and value of co2 formed = ?) if possible give the details of the calculations. tnx in advance - Jake