Hello All, 

In PMBOK the following two formulas are provided with regards to ETC calculation:

1. Re-estimate

2. EAC-AC

However in various (free tests - ie. pmprepcast) i have found that the following formulas are used (in addition to the above):

ETC (atypical) = BAC-EV

ETC (typical) = (BAC-EV)/CPI

During my prep for the exam, whenever I am in doubt I always refer to PMBOK. Since PMBOK does not have the above two formulas explicitly mentioned, (although I know that they can be derived from EAC formulas), should I know them for the exam? 

Thanks,