Direct Inverse Proportion (Percentage Change)

Ask any secondary 2 student in Singapore which is the toughest math topic and most of them will tell you it is Direct/Inverse Proportion. Overall, this is actually a very easy chapter, except for a particular kind of question: Questions with percentage increase and proportions. So why do students find this kind of question difficult? The biggest hurdle is to get over the fact that each algebra alphabet (x or y) can represent more than 1 value. In secondary 1, they have been d