Return on investment = (Income - Cost) / Cost
In this case, the Income = $290,000
The costs = ($55/m + $315/m +$50/m) • 60m = $25,200
Real estate agent fee = $290,000 • 0.05 = $14,500
Original purchase price = $200,000
Total costs = $25,000 + 14,500 + 200,000 = $239,700
Income = $290,000 - 239,700 = $50,300
Return on investment = ($290,000 - 239,700)$200,000 = 0.2515 = 25.15%
But, the profit was gained over 5 years, so the average return was 25.15% / 5 = 5.03% per year.