Numbers Check Please - Investment Duplex, Net ROI

[Sam B.]

I'm requesting feedback on my numbers, please:

Duplex @ 100k, Financing with Investor Mortgage w/25% down, Balance @ 5% on 30yr. No rehab required, currently rented, gross both sides @ 1300/mo.

Cash Invested (Down Payment) 25k
Mortgage 75k @ 5% on 30 Yr = 405/mo
Net Rent (50% Rule) = 650/mo
Net Cash Flow = 245/mo
Cash on Cash ROI = ~11.76% Annually (245*12/25000)

Any comments on how my numbers are being processed?

Thanks all.