In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Input: Consider Input: Article: One of the tough things about being a high school student is that you never seem to get enough sleep at night, which often leaves you nodding off during classes. "The best amount of sleep to get is about seven and a half to eight hours," Peter Venn at Queen Victoria Hospital, UK, told The Telegraph. Spending either less than six or more than nine hours in sleeping puts your health at risk. A popular solution to a lack of sleep at night is to take a "power nap" during the day, but does this work? Generally speaking, it can be beneficial. Research shows that a nap in the middle of the day --even a brief one as short as five or 10 minutes ---can clear your mind and leave you with increased energy and improved productivity , according to Forbes. However, as refreshing as it might be, if you are getting adequate sleep at night, taking a power nap isn't such a wise choice. The reason is that sleeping during the day can interfere with your body's biorhythms . The brain gets used to going to bed at roughly the same time each night and getting up at the same time each day, and you don't want to disturb this routine. One more thing to keep in mind is that a power nap should never be used as a replacement for a good night's sleep. "Twenty minutes of power nap during the day is not like a tablet which will definitely work," Rahul Mukherjee, an Indian sleep specialist, told The Telegraph. "An hour's sleep before midnight is worth a couple of hours' sleep after midnight."
Answer: About seven and a half to eight hours.

Output: What is the healthiest amount of sleep for the majority of people according to the article?

Input: Consider Input: Article: My wife and I have always been friendly with the clerks at the local convenience store. I don't think many people appreciate what a difficult job these folks have. They work for a little over minimum wage and I often wonder how they make ends meet. One of the clerks, Charlie, was always wearing his glasses but he didn't one day. I asked him about it and he said they'd been out of order and that he couldn't afford a new pair. His family needed money. It was obvious that he was having a difficult time. We wanted to help him, so we turned to our own eye doctor for assistance with a plan. We had his secretary contact him, asking him to come in for an eye exam for free. We told the doctor to let him order whatever glasses he wanted and that we would pay for them. Although Charlie questioned what was going on, the doctor just told him that someone had offered the money for his new glasses. When we went in to pay the bill, the doctor told us he was so touched by our idea that he _ the exam fee and only charged us for half the price of the glasses! It was so wonderful to see Charlie in her new glasses and he enjoyed telling all the regular customers how the gift came about. I'm sure that upon hearing her story, ideas of kindness may have emerged in the minds of many.
Answer: His old glasses were broken.

Output: Why didn't the clerk Charlie wear glasses one day?

Input: Consider Input: Article: Metro Pocket Guide Metrorail Each passenger needs a farecard to enter and go out. Up to two children under ago five may travel free with a paying customer. Farecard machine are in every station, Bring small bills because there are no change machines in the station and farecard machine only provide up to $ 5 in change. Get one of unlimited Metrorail rides with a One Day Pass. Buy it from a farecard machine in Metro stations. Use it after 9:30 a. m. until closing on weekdays, and all day on weekends and holidays. Hours of Service Open: 5 a. m Mon-Fri 7a. m. Sat--Sun . Close: midnight Sun--Thurs 3 a.m. Fri.---Sat. nights. Last train times vary. To avoid missing the last train, please check the last train times posted in the station. Metrobus When paying with exact change, the fare is $ 1. 35 . when paying with a smarTrip card, the fare is $1. 25 Fares for the Senior /disabled customers Senior citizens 65 and older and disabled customers may ride for half the regular fare. On Metrorail and Metrobus, use a senior/disabled farecard or SmarTrip card. For more information about buying senior/disabled farecards, farecard or SmarTrip cards and passes, please visit MetroOpenDoors. com or call 202-637-7000 and 202-637-8000. Senior citizens and disabled customers can get free guide on how to use proper Metrobus and Metrorail services by calling 202-962-1100 Travel tips . Avoid riding during weekday rush periods -before 9:30 a. m. and between 4 and 6 p. m. . If you lose something on a bus or train or in a station, please call Lost & Found at 202-962-1195.
Answer: They make change for no more than $5.
Output: What should you know about farecard machine?