A, B and C are 3 varieties of beer which contains starch, hops and water in varying proportions. A contains x% starch and y% hops. B contains y% starch and y% water. C contains x% hops and y% water. When A, B and C are mixed in the ratio 2:3:5, then the final mixture has 38% starch and 28% hops. Find the sum of x and y?