Show that the thermal efficiency of a combined gas-steam power plant cc can be expressed as

where g = Wg /Qin and s = Ws /Qg,out are the thermal efficiencies of the gas and steam cycles, respectively. Using this relation, determine the thermal efficiency of a combined power cycle that consists of a topping gas-turbine cycle with an efficiency of 40 percent and a bottoming steam-turbine cycle with an efficiency of 30 percent.

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Nee = 7g + n - ngMs