Land & Building Additions

I have got some problem in calculating the Land & building additions in the cash flow question. The link is attached and the question (Q 4) can be viewed there clearly.
June 2005 Q 4

The following supporting information is available:
(i) Details relating to the non-current assets are:
Property, plant and equipment at:
At 31 march 2004 Land and Buildings
Cost/Valuation = 500; Depreciation = 80 ; Carrying Value = 420
At 31 march 2004 Plant
Cost/Valuation = 445 ; Dep = 105 ; Carrying Value = 340

At 31 march 2005 Land and Buildings
Cost/Valuation = 600 ; Depreciation = 12 ; Carrying Value = 588
At 31 march 2005 Plant
Cost/Valuation = 440 ; Dep = 148 ; Carrying Value = 292

Casino revalued the carrying value of its land and buildings by an increase of $70 million on 1 April 2004. On
31 March 2005 Casino transferred $3 million from the revaluation reserve to retained earnings representing the realisation of the revaluation reserve due to the depreciation of buildings.
During the year Casino acquired new plant at a cost of $60 million and sold some old plant for $15 million at
a loss of $12 million.

This is how i go on to calculate the Additions
First calculating dep.
80-70-12= 2 Depreciation charge for the year
Now if i make land and building account based on {cost} not {carrying value} to calculate additions to the land and buildings during the current year then it should just be 600 -500 = 100.
Likewise calculating it through NBV method additions will be
420 + 70 – 12 – 588 = 110 Additions
Now see the difference of 10? between the two methods. i can’t figure out why this occurs. Actual additions are 110 whereas if i were to calculate it through Land and Building cost account in the exam i would have been wrong. My mind has stopped working for now. maybe m doing some silly mistake. Please Let me know