1. The problem statement, all variables and given/known data An ideal simple gas turbine has a compression ratio of 5. What is its 2. Relevant equations c=r(γ-1/γ) η=1-(1/c) 3. The attempt at a solution I'm stuck, I think I need to use the above equations and possibly more. I just don't know how to find a value for the ratio of specific heats,γ.