Cosima is in the business of importing hand-loomed Guatemalan shirts for the Fair Trade gift shop in town. The shirts cost her a certain amount, and her profit, when she sells them to the gift shop, is x% of what they cost her. (Then the gift shop marks the price up some more and sells them to the public, but that isn’t relevant.)
Cosima has now found a second source of shirts, from Peru. These cost her 8% less than the shirts from Guatemala. She sells the Peruvian shirts to the gift shop at the same price as the Guatemalan shirts, and because they cost her less, her rate of profit is higher: (x + 10)%. This information is enough for you to figure out what x is.