To answer the question about sneakers:
We know that the price we have now is only 75% of the original price. That would mean that the original price could be found by adding the extra 25%. Let's find 1%. You could also find 5%, 25%, or anything else that is easy for you, but we are going to do it as 1%.
Do the price divided by 75, and then multiply it by 100 to get the full price.
If you wanted an explanation on the one below, tell me.