if the question is asking about the minimum fuel at take off: You will have to consider 3 weights which are:

1) 2950 KG
2) 2725 KG + flight fuel/burn off
3) 2630 KG + fuel at start up/take off

Then you choose the least and use it?

If the question asks about max fuel at take off:

you will consider only the maximum weights which is 2950 KG and Maximum landing limit weight wich is 2725+flight fuel?

Need clarification on this.

Can you post the question as it was written so that we have a more useful starting point for discussion ?

If you want to pass the Performance exam you would do well to purchase one of Bob's books (or E-books).

At the very least, Bob's practice questions will make a lot more more sense.

Just a thought!

Looking forward to purchase it

Let's assume that the trip fuel for a given flight is 125kg and no limitations are imposed by runway lengths. Then the three checks for the take-off limit would be the least of:

Take off limit = 2950kg (structural limit)
Landing limit (2725kg) + burn-off = 2850kg
Max ZFW (2630kg) + all fuel on board = ???? this is what you are trying to find.

However, if ZFW was the problem, you could always go up to the next highest limit, 2850kg, providing the extra weight was fuel only. Adding extra fuel does not change the ZFW. In an exam question, the examiner would have to give you the empty aircraft weight, the pilot's weight, the passengers' weight and the cargo weight in the question text. So you would always know the actual ZFW (if that was greater than the maximum ZFW permitted, it's the examiner's fault for writing an invalid question!)

If a question asks for maximum fuel, there is no point checking the ZFW condition.

Passed my cpl performance today with only 70%..just a pass..Thank you very much for all the helps here in the forum.

Congratulations Jukzizy. It's been a steep climb so enjoy the view!!