Aperson packs two identical coolers for a picnic, placing twenty-four 12-ounce soft drinks and 5 pounds of ice in each. however, the drinks put into cooler a were refrigerated for several hours before they were packed in the cooler, while the drinks put into cooler b were at room temperature. when the picnickers open the two coolers three hours later, most of the ice in cooler a is still present, while nearly all of the ice in cooler b has melted.\