Two quantities that vary directly simply means that one quantity is directly correlated with the other quantity. When one is negatively or positively impacted, the other quantity is also negatively or positively impacted. For example, if an individual is making a recipe for a group of people, the amount of ingredients necessary will directly correlate with the amount of people eating. If the recipe calls for 2, but is feeding 10, then it would be ideal to do 5 times of every ingredient to have enough food to feed 10 people. As the amount of people increase, the amount of food also increases, as it is a direct relationship