The Calculation of simple yield:

The Return*
(Winnings)
__________ X 100= ROI (%)

Investment*
(Stakes)


so for example: I have 1000 bets with odds 2,00
500 of them are winning and 500 losing. So i am on 0 and my ROI is zero

Would like to get right odds to have 15% yield,
How to calculate on what odds should i be to have ROI 15% ?
Because odds are not always 2,00 - they are different but i gave 2,00 as
example...

So, i know what are odds to have 0% yield, but would like to get with
some formula odds to have 15% yield (ROI)!?

Thanks very much for help!
Ivica