When working out the Project Specific cost of equity the calculation is Rf+(Beta * Market Premium). However in a similar question earlier in the exam (Q16) the calculation is slightly different Ke=Rf+Beta*(Erm-Rf).
Maybe I’m just conflating two different topics but I’m trying to workout is why does one question ask you for the difference between Erm and Rf but in the latter question you expected to use only Erm