Doubt on a question's correct answer

Submitted by jvleminc on Wed, 07/17/2013 - 03:25
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Q: An activity has an ES of day 3, an LS of day 13, an EF of day 9 and an LF of day 19. What is the activity's duration. 

The given answer is: LS-ES = LF-EF = 13-3 = 19-9 = 10. (PM Fasttrack 7, id 454)

 

My doubts is that the above formulas calculate the float, not the activity's duration, while the duration is calculated as EF-ES or LF-LS (used in the critical path drawings). So the duration would be 9-3=19-13=6.

Can anybody confirm or clarify my doubt? Thanks in advance.

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pmpnewster

Wed, 07/17/2013 - 03:53

 

The activity duration will be either 6 (by 0 start method) or 7 (using 1 start method).

I know it sounds inconsistent, but the question lends itself to dual interpretation by not clarifying which method to use. Chances are you will not see such questions on the real exam.

 

Regards.

 

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jvleminc

Wed, 07/17/2013 - 04:04

Good, so anyway you're going with my solving technique and not with that Fastrack indicates :-)

Shee

Wed, 07/17/2013 - 04:15

 LS = LF - D + 1

13 = 19 - D + 1

 

D = 7 DAYS

 

Float = LS -ES or LF - EF 

pmpnewster

Wed, 07/17/2013 - 04:34

 

Now that I look at it closer, it seems that they intended to ask for float, but inadvertently are asking for duration. Why do I think so? Because:

i) They seem to have given the calculations and explanation for calculating float

ii) Asking for duration with the given data is open to dual interpretation. I don't believe FastTrack would do that.

Note: I am not a FastTrack user.

 

You might want to point this out to them. I am certain they will fix it.

 

Regards.

 

 

 

 

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jvleminc

Wed, 07/17/2013 - 05:04

Yes, I think the question is stated wrong, or the answer :-) 

Thanks for the input, it's the first time I found such a question in Fastrack.

cool_dude_shandy

Wed, 07/17/2013 - 17:19

I checked and in my fastrack its showing 6 as the right answer.

 

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jvleminc

Fri, 07/19/2013 - 13:59

Ha, so they corrected it :-) In My Fastrack it's still showing as 10 (rechecked it right now).