Effect on accounting equation question- Disposal of NCA

[24309]

Just say you had the following in a disposal of NCA with a trade in allowance (and bought a new one): Question 1.5.2 NEAP 08

Disposal of Vehicle: 32000
                 Vehicle: 32000

Acc dpn of vehicle: 22400
          Disposal of vehicle:22400

Sundry creditor-xy 12000
      disposal of vehicle: 12000

Dispsoal of Vehicle: 2400
           Profit on disposal: 2400

New Vehicle: 49990
GST Clearing: 4999
  Sundry cred-xy 54989

What would the effect on Assets, Liabilities and OE be? (including dollar values)

Solution suggest this but i dont get it....
A- increase- 40390
L- increase- 37990
OE- increase- 2400

[greenefish]

A- increase by 40390. to get this you have to minus the accum depn of the vehicle from the original cost of the vehicle to get its carrying value (32000-22400=9600) you then minus this from the new vehicle (49990- 9600= 40390) this gives you the increase in the assets
L- is just the cost of the new vehicle minus the trade in value (49990-12000=37990)
O- is just the profit from the disposal (2400)

hope that helped