Bill is doing weight training before trying out for the boxing team. He gets two 2-gallon jugs and fills them 70% full with sand. If sand has a density of 5 pounds/gallon, how many pounds do Bill's improvised weights weigh? Think carefully first, then make a decision:
First find the volume of the sand in one jug: 2 gallons * 70% = 1.4 gallons. Then double this amount since there are two jugs: 1.4 gallons * 2 = 2.8 gallons. Then multiply the total volume by the density of sand to find the total weight: 2.8 gallons * 5 pounds / gallon = 14 pounds. So, the answer is 14.