Financial calculation for rate of return

[Kathryn Bangs]

How do I calculate my real rate of return if I buy a $43k deed of trust for $40k that pays interest of 8% and matures in 43 days?

I know calculation for annual rate of return but, my $ are invested shorter term and I’m not sure how to throw that in the mix to figure out what return really is.

Thanks for any insight.