If you want at least 3 pounds of hamburgers, then $6 is enough to buy those 3 pounds of hamburgers. If you ONLY buy 3 Pounds, then you also have enough for 4 pounds of chicken. $3 a pound x 4 = $12. You have 2 dollars left to spare, which means you can buy another pound of hamburgers. So 4 pounds each are able to be purchased.