Mike is having a party but he forgot to put the soda on ice. He remembers his high school science class, where he learned that if you add salt to ice, it makes the mixture colder than pure ice. He designs an experiment to see what amount of salt is needed to cool a can of soda to 15ºC, the optimum drinking temperature. He starts by getting four identical coolers, each with a 5 pound bag of ice in them. He leaves pure ice in the first cooler, in the 2nd cooler he adds 100g of salt, in the 3rd 200g of salt, and in the 4th 300g of salt. He then puts a room temperature soda can in each cooler, and waits for 10 minutes. At the end of 10 minutes, he takes out each can, opens it, and measures the temperature of each soda with a thermometer.