You get to the gym and it's packed. The weights are taken, the machines are filled, and you don't have time to wait.
Grab 3 weights - 2 plates (these are 10 lb) and one heavy dumbbell. If you'd rather use dumbbells and can find the weights you're looking for, go for it! But on busy nights, I generally can't find any of the weights I want but there's always an abundance of plates and always at least one heavy dumbbell sitting around. The only other thing you need is a spot off to the side, and your favorite music in your ear!
I did 3 reps to show you what to do, but you do 10. Do three sets, stopping for 30 seconds between each and viola! A full-body, carioized workout!