IAS 20 Government grants

Hello,
I have a few questions regarding IAS 20. I find that this topic is quite confusing. The following questions are from BPP F7 study text. Sorry for the messy presentation. I could not find a way to present it in a proper way.

Question 1:
Arturo Co receives a government grant representing 50% of the cost of a depreciating asset which costs $40,000. How will the grant be recognised if Arturo Co depreciates the asset:
a) over 4 years straight line
b) at 40% reducing balance

Answer:
a) Straight line

Year_______Depreciation_____________Grant income
1 _______10,000__________________5,000
2 _______10,000__________________5,000
3 _______10,000__________________5,000
4 _______10,000__________________5,000

b) Reducing balance

Year________Depreciation____________Grant income
1 ________16,000_________________8,000
2 ________9,600 _________________4,800
3 ________5,760 _________________2,880
4(Remainder) 8,640 _________________4,320

Question 2:
A company receives a 20% grant towards the cost of a new item of machinery, which costs $100,000. The machinery has an expected life of 4 years and a nil residual value. The expected profits of the company, before accounting for depreciation on the new machine or grant, amount to $50,000 per annum in each year of the machinery’s life.

Answer:

a) Reducing cost of the asset
_________________________Year 1_____Year 2_____Year 3_____Year 4_____Total
Profit before dep.___________50,000____50,000____50,000_____50,000____200,000
Dep.*____________________(20,000)___(20,000)___(20,000)___ (20,000)___(80,000)
Profit____________________30,000____30,000_____30,000_____30,000___ 120,000

*The depreciation charge on a straight line basis, for each year, is 1/4 of (100,000 -20,000) = 20,000

Statement of financial position (extract)
_________________________Year 1_____Year 2____Year 3_____Year 4
Non-current asset__________ 80,000____80,000____80,000_____80,000
Dep.____________________(20,000)____(40,000)___(60,000)___(80,000)
Carrying amount___________ 60,000_____40,000____20,000____ –

b) Deferred income

_________________________Year 1_____Year 2_____Year 3_____Year 4_____Total
Profit before dep.___________50,000____50,000_____50,000_____50,000___ 200,000
Dep.*____________________(25,000)___(25,000)___(25,000)____(25,000)__(100,000)
Grant____________________5,000______5,000______5,000______5,000____20,000
Profit____________________30,000_____30,000_____30,000_____30,000_____30,000

Statement of financial position (extract)

Non-current asset (cost)______Year 1_____Year 2_____Year 3_____Year 4
Profit before dep.___________100,000___100,000___100,000____100,000
Dep.*____________________(25,000)___(50,000)___(75,000)____(100,000)
Carrying amount____________75,000____50,000____25,000______ –

Deferred income___________15,000_____10,000_____5,000_______ –

My questions are:
1. What are the debit and credit entries for both of the answers?
2. For question 2(a), if the non-current asset is reduced by 20,000 (credit), where would the debit entry go to?
3. For question 2(b), if the deferred income is recognised (debit), where would the credit entry go to?

Thanks.