Answer: [tex]33.2\%[/tex]
Explanation:
Given
83% heat is transferred and out of this, only 40% is converted to the mechanical energy of spinning turbine.
The overall efficiency is the product of all the efficiency i.e.
[tex]\eta_t=0.83\times 0.4\\\eta_t=0.332\ \text{or}\ 33.2\%[/tex]