You don't give interest rate, but assuming 6.5% IO, then:
Expenses
Interest pa $315,000 x 6.5% = $20,475
Running costs est 20% of rent = $4,680
Total Expenses = $25,155
Income
Rent = $23,400
Profit = Income - Expenses
Profit = $23,400 - $25,155 = $1755 LOSS
But, this is not...