[tex]\rho_{petrol} = 0.75 \ g/cm3 = 7.5\cdot10^{-4} \ kg/cm3\\\\1 \ L = 1000 \ cm^3\\donc \ 120 \ L = 1.2\cdot10^5 \ cm^3\\\\\\V_{petrol} = 1.2\cdot10^5 \ cm^3\\\\m_{petrol} = V_{petrol} \cdot \rho_{petrol}\\= 1.2\cdot10^5 \ \cdot \ 7.5\cdot10^{-4}\\= 90 \ kg[/tex]
