Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Our solar system has only one star. But many stars are in systems of two or more stars. Two stars that orbit each other are called a binary star system . If more than two stars orbit each other, it is called a multiple star system. Figure below shows two binary star systems orbiting each other. This creates an unusual quadruple star system. Answer: one
Output:
How many stars are in our solar system?