You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You need to come up with a question about the story that requires an understanding of the relationship described in the background paragraph. The generated question should not be answerable without both the background and story. Write a question about the story that requires a relationship in the background paragraph to answer. Check whether your question requires both the background paragraph and the story to answer. If your question can be answered by only one of these, try to rewrite your question so that it requires both. Note that "flipping" a word in the question can give rise to a new question where the answer will be different from the original question. Often, "flipping" a word gives rise to flipping the direction of the relationship, for example, from "increase" to "decrease."

[Q]: Background Paragraph: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. 
Story: Peter visited two mountain ranges last summer. The Ozarks in Missouri, and the  more massive and younger Colorado Rockies. He loved both ranges, but liked the caves systems and blue holes in the Ozarks a bit more.
[A]: Which mountains have a larger percent of limestone?


[Q]: Background Paragraph: Turner et al (2006) derived crash prediction models for this report’s predecessor and found a
pronounced ‘safety in numbers’ effect in the models. Using the crash prediction model for mid-block
locations, generic motorist and cyclist volumes can be used to demonstrate the impacts on the
expected crash rate of varying motor vehicle and cycle volumes. As shown in figure 2.20, an increase
in the proportion of cyclists to the overall traffic volume causes an increase in expected crashes at
mid-block locations, but the crash rate increases at a decreasing rate. That is to say, the crash rate per
cyclist goes down as the cycle volume increases. 
Story: Motorcycle fest lasted a week in the city. On Monday, there were 500 motorcycles on the road. On Tuesday, there were 600 motorcycles on the road. On Wednesday, there were 700 motorcycles on the road. On Thursday, there were 800 motorcycles on the road. On Friday, there were 900 motorcycles on the road. On Saturday, there were 1000 motorcycles on the road. On Sunday, there were 1100 motorcycles on the road. The festival generated a lot of revenue for the city.
[A]: What day was the crash rate per cyclist lower: Friday or Sunday?


[Q]: Background Paragraph: During late adulthood, the risk of developing diseases such as cardiovascular diseases and cancer continues to rise. Most people also have a decline in strength and stamina. Their senses may start failing, and their reflex time typically increases. Their immune system also doesn’t work as well as it used to. As a result, common diseases like the flu may become more serious and even lead to death. The majority of late adults develop arthritis, and as many as one in four develop Alzheimer’s disease. 
Story: Mike is studying the population growth rate of countries around the world. He noticed that countries like Japan and Russia are having a demographic shift. They have a growing population of late adulthood. He recorded the late adulthood population as population A. On the other hand, many developing countries have growing population of younger people. He recorded younger population as population B.
[A]:
Which population would be less at risk of cancer or Alzheimer's disease, population A or population B?