How can I make a 10% return on a $5k investment in 90 - 120 days?

As close as I can get or more to the amount above is what I'm looking for. I also need to know how much risk is involved (high, medium, low).

That works out to a 40% annual return. There are no public type investments where you can expect that type of return.
A high yield bond fund might pay 12% annual return. So you will just have to speculate on a one or a few stocks, or some volatile mutual fund that invests small cap stocks, small country bond/stocks, or something like that. You could also lose a lot of your money also. Good luck.

The only way it's possible is if you invest in high risk investment, and this is not recommended. It your a risk taker, go to a casio and gamble part of it. Because that has the same risk as some high risk investments.

Here's a method i found in a book.
If you're becoming a landlord:
Find an improvement that you could make to the house you are renting.
Make it happen.
Get a new appraisal and new mortgage.
IF CALCULATED PROPERLY, you can use the rent the tenant gave you to pay off the improvement and mortgage, and get a big wad of borrowed money that you got when getting a new mortgage.
For more info, read p.112 or Real Estate Riches by Dolf De Roos.
Oh, and there is pretty much no risk...
If you're into stocks and bonds:
Sorry...Not studying that.

Risk - high. 10% return - lend your money in 10 equal portions of 500 each at www.prosper.com. What I am saying is that you can potentially earn around this much or close to it, but your risk will be completely spread out through loans. Check them out and read on carefully. This is not a promotion.

I've been getting 10% MONTHLY interest on my money for a good 6 months now... it's great!

https://www.legisi.com/ref/?id=thispays

If you put $5,000 in this at 10% MONTHLY interest on the 120-day plan and let it compound then in 120 days it will be $7,320. : )

If interested then HURRY because this program is going private JUNE 1. So, there's only a few weeks left to get in. Oh, and after that there will be one plan that pays 6% MONTHLY, which doubles your money every year if you let it compound.

Anyway, I just thought I'd tell you about this. Do with it what you want. : )