Actually, a lot of people are confounded with percent problems that they don’t understand.
One of the issues I’ve seen is the question of whether the base for the percent calculation is the old number (usually) or the new number (when you want to confuse someone).
In your problem, 75 is offered for something which costs 56. So the % should be based on the 56. 19 is what % of 56. But that is not what is in question, the question is what % of the 75 is to be returned? 19 is what % of 75. When the cost is 56. To me the issue really is why is the % change important?
During World War Two, I heard that school boards cut teachers’ salaries by 10%. After the war, they increased the teachers’ salaries by 10%. Then the school boards wondered by the teachers were fussing.