Profit Rent = £20,000
Investors return @ 9% = 49,000 x 0.09 = £4,410
Amount to invest in SF (gross of tax) = 20,000 - 4,410 = £15,590
Tax @ 40% = 15,590 x 0.4 = 6,236
Available to invest in SF (net of tax) = 15,590 - 6,236 = £9,354
Amount of £1 per annum for 5 years @ 2.5% (5.256) 9,354 x 5.256 = £49,164
SAY £49,000