Quantities will be in direct proportion when they increase or decrease at the same rate, that is, if one quantity is multiplied by a factor, then the other quantity is also multiplied by the same factor. However, quantities may not be in direct proportion when there are other factors affecting them, such as external forces or limitations. For example, the amount of time spent exercising and the number of calories burned may not be in direct proportion if the person's metabolism or level of exertion varies. Additionally, some relationships may be more complex, such as inverse proportion, where two quantities change in opposite directions. Therefore, whether quantities are in direct proportion or not depends on the specific factors influencing them.
