Question #10 is located in your PM Formulas PDF file I downloaded. The question reads:
PV = 100, EV = 105, BAC = 400, AC = 102 and CV = 3? What is the Estimate to Complete (ETC)?
Your explanation to the answer is understood, however, to calculate EAC you used EAC = AC + (BAC - EV). There are 3 formulas in which to calculate EAC (i.e. Not valid, atypical, typical), which is why i asked the question of why you used the "atypical" formula to arrive at your answer?
EAC "not valid" = AC + ETC
EAC "atypical" = AC + BAC - EV (this is the equation you used)
EAC typical = BAC/CPI
I recently failed the PMP and was not able to answer any of the more than 20 math equations so I'm on edge about every possible question/answer as it relates to formulas. I thank God i was able to find your formula site online. It has been great thus far.
I need a bit more information to answer your question: Would you please tell me where exactly your saw this question? We provide thousands of questions and "#10" doesn't tell me much in regards to where to look for it. What document, website or tool did you find this in?
for calculating EAC why did you use AC+BAC-EV? The question does not state if assumption was not valid, atypical, or typical and the default formula is BAC/CPI. I'm confused at how you arrived at the answer.