Refer to figure.
Traffic Load (TL). The total mass of passengers, baggage and cargo, including any ’non-revenue’ load.

Dry Operating Mass (DOM). The total mass of the aeroplane ready for a specific type of operation excluding usable fuel and traffic load. The mass includes items such as crew and crew baggage, catering and removable passenger service equipment, potable water and lavatory chemicals, food and beverages.

Operating Mass (OM). The DOM plus fuel, but without traffic load.

OM = DOM + fuel = 35 600 kg + 11 700 kg = 47 300 kg

For this question, we will consider the take-off and landing situations, subtracting from the Maximum Permissible Take-off Mass and the Performance Limited Landing Mass limits the OM, the TL and the fuel masses (as required), to figure out if the aircraft is overloaded or underloaded:

• Max TOM - OM - TL = 62 800 - 47 300 - 14 200 = 1300 kg​​​​
• Max LM - (OM- Trip fuel) - TL = 54 900 - (47 300 - 7700) - 14 200 = 1100 kg underload

We will select the lowest of the two numbers and the "+" sign indicates that it is underloaded by 1100 kg.

positive result (+) → underload
negative result (-) → overload

Note: Be careful to avoid any double mass calculations, due to the fact that some masses are already included in other masses, e.g. fuel mass is included in OM, crew and crew baggage mass is included in DOM, DOM is included in OM and so on.