I do not understand why Lae Ltd maximum surrender value is 29,900.
Trading Loss (18,100)
Property Business Loss (26,700)
Loan Interest Receivable 1,600
Capital Loss (19,200)
Qualifying Charitable Donations (4,800)
The property business loss and the qualifying charitable donations can be surrendered to the extent that they are unrelieved, so £29,900 of these can be surrendered (26,700 + 4,800 – 1,600).
The amount of loss available for group relief from Lae Ltd is the unused trading loss (18,100) plus the excess property business loss and excess qualifying charitable donations (29,900 – the calculation of which you have correctly shown) which totals 48,000. Not sure therefore what figure(s) you do not understand?