Can someone tell me how to do these problems, I keep getting stuck on them: "find the value of x"

At the school fair, grade 3 raises 84 more then grade 4. grade 4 raises 112 more then grade 2. grade 3 raises 360. how many dollars does grade.2 have

What is the greater volume 72 quarts or 23 gallons

Im gonna fail 7th grade selective breeding 1. creates offspring which are genetically identical to the parent 2. is the process of breeding only organisms with desirable traits 3. involves the removal of the nucleus of a cell 4. combines traits from organisms of different species