10ml of hydrocarbon on complete combustion gives 30ml of CO2and for  this 40ml of O2 is required. Then the Molecular Formula of hydrocarbon is ____?

CxHy+(x+y/4)O2→xCO2+y/2H2O(l) 1V        (x+y/4)V        xV        0Now, V = 10 ml10x = 30     x =  3(x+y/4)×10=40⇒3+y/4=4∴  y=4Molecular Formula   C3H4