I solved the problem, but I can't get the right unit for the answer. A Carnot engine whose low-temperature reservoir is at 16°C has an efficiency of 31%. By how much should the temperature of the high-temperature reservoir be increased to increase the efficiency to 70%? My numerical answer is 544.8. I tried Kelvin first - the most obvious choice - but that was wrong. Then I tried celcius and J/K. I tried to work it out but I have no earthly idea - the other choices include: - C0 (like the celcius sign but the circle is after the C) -J/kg*K -J/mol*K and -kJ/kg Any help would be grately appreciated.