Put your 100 dollars in a savings account, you would not gain much in 6 months, maybe 45 cents at the most, but you wouldn't lose anything, this could be betting that your dad trys something more risky and loses some money... that's how I would do it

I would do the opposite and buy a stock with great potential upside potential. Something Warren Buffet suggests. Win big or lose say I.

Buy old, used electronics from neighbors and yard sales. Then take them back to your workplace and carefully(make sure you do it carefully to not damage anything) take the products apart. Sort them and sell the parts individually. It may seem crazy, but many will but these items especially if it relates to computers. People like to collect parts and build their own electronics to save money and in some cases, a better product. This method works really well because if you make the prices of the individual parts high enough to make reasonable profit, but still seem reasonable to the customer, you can easily earn double than what you've spent.

My dad and I are having a contest where we each start with 100 dollars and in 6 months whoever has made the most money wins. The prize is honor. Please help me with advice on what to invest in or how to spend my money to gain the most. I really have no clue what I could do with my money so im open to all suggestions.