【微臣数学难题班讲义集锦

《【微臣数学难题班讲义集锦》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、难题集锦A1.Ifjandkareevenintegersandj

2、herearecurrently10peoplebehindShandra.If3ofthepeoplewhoarecurrentlyinlineaheadofShandrapurchaseticketsandleavetheline,andnooneelseleavestheline,therewillbe8peopleaheadofShandrainline.Howmanypeopleareinthelinecurrently?4.AandBareindependentevents,andtheprobabilitythatbotheventsoccuri

3、s1/2.WhichofthefollowingcouldbetheprobabilitythateventAoccurs?Indicateallsuchprobabilities.A.0B.1/4C.1/2D.3/4E.15.Howmanypositiveintegerslessthan10,000aresuchthattheproductoftheirdigitsis210?A:24B:30C:48D:54E:726.Fromagroupof8people,itispossibletocreateexactly56differentk-personcomm

4、ittees.Whichofthefollowingcouldbethevalueofk?Indicateallsuchvalues.A.1B.2C.3D.4E.5F.6G.77.Yesterday’sclosingpricesof2,420differentstockslistedonacertainstockexchangewerealldifferentfromtoday’sclosingprices.Thenumberofstocksthatclosedatahigherpricetodaythanyesterdaywas20percentgreate

5、rthanthenumberthatclosedatalowerprice.Howmanyofthestocksclosedatahigherpricetodaythatyesterday?A.484B.726C.1,100D.1,320E.1,6948.Ofthestudentsinaschool,20percentareinthesciencecluband30percentareintheband.If25percentofthestudentsintheschoolareinthebandbutarenotinthescienceclub,whatpe

6、rcentofthestudentswhoareinthescienceclubarenotintheband?A.5%B.20%C.25%D.60%E.75%9.ThecompanyatwhichMarkisemployedhas80employees,eachofwhomhasadifferentsalary.Mark’ssalaryof$43,700isthesecond-highestsalaryinthefirstquartileofthe80salaries.Ifthecompanyweretohire8newemployeesatsalaries

7、thatarelessthanthelowestofthe80salaries,whatwouldMark’ssalarybewithrespecttothequartilesofthe88salariesatthecompany,assumingnootherchangesinthesalaries?A.Thefourth-highestsalaryinthefirstquartileB.ThehighestsalaryinthefirstquartileC.Thesecond-lowestsalaryinthesecondquartileD.Thethir

8、d-lowestsalaryinthe