This is a 3-step question

step1. 56000-1100 54900kg = TAS 437kt -5degrees =TAS 432kt

step2. No distance given so NAM = TAS*TIME:60 = 346NAM

step3. From the table

Startmass -----> Range

54900 -----> 3736 (subtract NAM 346) = 3390

3390 on the table gives around 52900 (interpolate) = Endmass

Startmass-Endmass = 54900-52900= 2000kg

Answer varies, depends how accurate you interpolate!!!!!

so: 3390 look this up on the table, then closest you will find is 3395 , so now (interpolate) to get around 52900

so: 2030 (or my answer 2000) comes from subtracting Endmass from Startmass!!

You have to apply the ISA -5 , so is -0.3% , but this won't change the answer to much!!!