["My friend bet me $20 in a swimming race across a lake last weekend. I took the deal because I am positive I'm a stronger swimmer!"]
$20 bucks?  I'd try to do it too.  How'd it go??
My friends and I were relaxing and swimming at a lake last weekend. My friend bet me $20 that I couldn't race him in a swim across the lake. I ended up winning because I knew I was a faster swimmer.