How many families own pianos? Say one out of three. Then there are about 250,000 pianos in Chicago. How often would each be tuned? Maybe once every five years. That makes 50,000 tunings a year. How many pianos can one tuner tune in a day? Four? And how many in a year? Assuming 250 working days, one tuner can handle 1,000 pianos a year. So there's work for approximately 50 piano tuners in Chicago -- which, as it turns out, is reasonably close to the actual number in the Yellow Pages. Why was guesswork so accurate? The law of averages is partly responsible. At any point, your assumptions may be too high or too low. But because of the law of averages, your mistakes will frequently balance out. By the way, the Mariana Trench is about six nautical miles deep, and a cannonball drops at a rate of ten feet per second. So it took the cannonball about an hour to reach the bottom.
Could this be guess? If you know Earth's highest point Mount Everest, is 29,000 feet, you might reasonably conclude that its lowest point would be close to the same distance. Then you might imagine that a heavy object would take one second to fall through the water of a 10-foot-deep swimming pool. These estimates would bring you close enough to the correct answer.
【2014届高考英语一轮复习话题阅读素材28】相关文章:
★ 贵州省贵阳市2014高考英语(新人教版)一轮阅读训练(21)附答案
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练:第19组(含解析)
★ 【北师大版】2014届高考英语一轮复习指导课时作业:Unit 10 B卷 Word版含解析
★ 2014届高考英语一轮复习课时作业(二十二)必修4Module 4《Great Scientists》(外研版)
★ 四川省2016届高考英语一轮复习课时作业(26) Module 2 A Job Worth Doing 外研版必修5
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ规范练:4(含解析)
★ 常熟市2014高考英阅读理解语一轮(暑假)训练题(10)及答案
★ 2014届高考英语一轮复习课时作业(三十一)选修6Module 1《Small Talk》(外研版)
★ 2017届高考英语(江苏专用)二轮复习高考单词5大记忆法课件:4.联想记忆法
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21