*This amount feeds my family fine, sometimes with a little leftover, so I would say it's enough for 4 adults. Plan for 3/4-1 cup of cooked rice per hungry adult! You can always adjust amounts to the number of mouths you have to feed.
*One way to add more flavor and stretch out the hamburger meat to feed more people is to add some chopped onions/garlic while browning meat and throw in a can of beans (drained) with the taco seasoning and water.