Problem: Which state of the USA has only one common border with a neighbouring US state?
Answer: maine

Problem: The countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, and Sweden all share a border with what large body of water?
Answer: baltic sea

Problem: How many moons has the planet Mercury?
Answer: none

Problem: Which long-running TV series first aired on UK TV in 1963?
Answer:
dr who