AIEEE 2009 Solved Paper

In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidizer. The reaction is CH3‌OH(I)+3∕2O2→CO2(g)+2H2O(I)
At 298K standard Gibb's energies of formation for CH3‌OH(I),H2O(I) and CO2(g) are −166.2, −237.2 and −394.4‌kJ‌mol−1 respectively. If standard enthalpy of combustion of methanol is −726‌kJ‌mol−1, efficiency of the fuel cell will be