Question: Richard, Jerry, and Robert are going to share 60 cherries. If Robert has 30 cherries, and has 10 more than Richard, how many more cherries does Robert have than Jerry?
Answer: 
Since Robert has 30, then 60 - 30 = 30 cherries are left to be shared by Richard and Jerry.
Richard has 30 - 10 = 20 cherries since Robert has 10 more cherries than him.
Jerry has 30 - 20 = 10 cherries.
So Robert has 30 - 10 = 20 more cherries than Jerry.