# Oliver Lehmann question

Pls help me with this question.I do not understand FF  relationship between act 2 and act  3 and FS+3 relationship between act 3 and 4 .Can anyone help solving it?

### Oliver Lehmann question

Calculation -

Act 1 + Act 2 + Lag of 1 day + Act 4 == 20+10+1+6 = 37

Activity 3 will finish two days before activity 2 finishes and activity 4 will start 3 days after activity 3 finishes.

so there will be one day lag between activity 2 and 4. activity 3 duration will be parallel to activity 2 so no need to add duration of activity 3.

Hi Pankaj,

### Act 1 starts on Day 1 and

Act 1 starts on Day 1 and ends on Day 20

Act 2 starts on Day 21 and ends on Day 30

Act 3 can end only 2 days before Act 2  is completed, that is Day 28 ( forget when it can start)

Act 4 can start only on 28 + 3 , that is Day 31

Act 4 takes 6 days to complete, that is 31 + 6 , Day 37

I remember taking a long time to figure out what this means, when answering O Lehman questions. But finally was able to figure it out.. I have never seen this kind of question in any other mocktest, neither for the real exam.

### HI Marcurie.I did not

HI Marcurie.

I did not understand when  you said

Act 3 can end only 2 days before Act 2  is completed, that is Day 28 ( forget when it can start).

FF relation ship is Act 2 should be finished before I finish Act 3.I finished Act 2 at 30th day.Here am not sure when  am starting Act 3 so why am assuming it should be finished by 30th day and applying lead 2 days to get 28 days.Please explain.This FF relationship confusing me.Because I have all liberty to choose when to finish Act3 as only dependency is Act 2 should be finished before this activity finishes.

### FF-2 between activity 2

FF-2 between activity 2 & activity 3 means,

Activity 3 can finish 2 days before Activity 2 finishes. Hence Activity 3 will finish on day 28. Since the relationship is FF, you need not worry about the start day of activity 3.

Hope this helps.

Regards,

Arun.

### Thanks Arun,But again am

Thanks Arun,

But again am confused wth this question.Pls check

http://www.pmzilla.com/float-question

why the duration is not 13 ?

cna you pls explain?

### As far as I know, the answer

As far as I know, the answer should be 13 days as the relationship given is FF+3.

Activity A will finish on day 10 and since there is a lag of 3 days for Activity B to finish, the total duration should be 13 days.

The explanation given by Chandra on that forum topic speaks about a Start to Start relationship with 3 days lag whereas the question talks about FF+3.

But if anybody has an explanation for answer as 12 days, it is much appreciated.

I have mentioned the question for easy reference.

activity A has a finish - to-finish relationship with activity B. Activity A has a duration of 10 days. activity B has a duration of 9 days with a 3 day lag. what is the total duration of activty a and B?

1.7 days
2.8 days
3.12 days
4. 9 days

Regards,

Arun.

### Why not 30 +3+6 = 39 days ?

Act-3 will finish on 28 days which is good. But Act-2 will finish only in 30 days. So it s after 30 days that both Act-2 and Act-3 will be done.

So I add 30 + 3 + 6 =39

Plaese explain what's wrong in this.

### Dear Amar,The 3 days of lag

Dear Amar,

The 3 days of lag time should be considered between activity 3 & 4. In your calculation, you have applied 3 days from that day activity 2 finishes, but the 3 day lag starts after activity 3 finishes. So,

20(activity 1) + 10(activity 2) + 1(since 3 days lag starts on day 28 (when activity 3 finishes) and ends on day 31) + 6(activity 4) = 37 days.

Please let me know if you are still confused.

Regards,

Arun.

### Solution

Answer would be 37 - look at leads (https://www.pmbypm.com/lead-lag/) & lags (https://www.pmbypm.com/faq-lead-and-lag/). Also check this to understand how much score is good in Lehmann tests - https://www.pmbypm.com/oliver-lehmann-pmp-questions/

BR
Praveen.

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