The document discusses direct and inverse proportions. It provides examples of each: - Direct proportion examples include mass increasing directly with the number of cans of milk, and cost increasing directly with the number of pens. - An example of inverse proportion is journey time decreasing inversely with speed - if a journey takes 20 minutes at 30 mph, it will take 10 minutes at 60 mph. - Charles's law states the volume of a gas is directly proportional to its temperature - if volume is 2.4 L at 600 K, volume will be 3.2 L at the same proportional temperature.