If your friend pays you back in a higher denomination than you gave them, check to see if they tried to scam you.

My friend came to me and asked to borrow $100, but I didn’t have $100 on me. I had $40 and a $50 and a $10 so I gave it to him. <br><br>A week later he paid me back a $100 bill and I didn’t think anything of it. I stuck it in my locker and went about my day. Later on in the day I pulled the $100 out to break it and it was actually and a $50.