1、Didyouknow?Inthedecimalnumbersystem(base10)tendifferentdigits,0to9,areusedtowriteallthenumbers.Inthebinarynumbersystem(base2)twodifferentdigitsareused,i.e.0and1.

　　Whichoneofthefollowingnumbersisnotavalidnumberinthe

　　octalnumbersystem(base8)?

　　A)128B)127C)126D)125E)124

　　2、Thenumberofdiagonalsthatcanbedrawninaregularpolygonwith

　　twentysides(icosagon)is_____.

　　3、Ifaandbareintegers,10??3=1,152??7=3,andthen379??6isequalto_____.

　　4、Twonumbersareintheratio2:3.When4isaddedtoeachnumbertheratiochangesto5:7.Thesumofthetwooriginalnumbersis____.

　　5、ThegreatestnumberofMondayswhichcanoccurin45consecutive

　　daysis____

　　6、Saulplaysavideogameinwhichhescores4forahitandlost6foramiss.After20roundshisscoreis30.Thenumberoftimeshehasmissedis____.

　　7、ThreegirlsA,BandCrunina100mrace.WhenAfinishes,Bis10m

　　behindAandwhenBfinishesCis20mbehindB.HowfarinmetreswasCfromAwhenAfinished?(Let’sassumealltheathletesrunataconstantspeed)

　　8、Theareasofthefacesofarectangulaboxare84cm2,70cm2and30cm2.Thevolumeoftheboxincm3is____.

　　9、Youhave3weights:1kg,3kgand9kgaswellasanequalarmbalance,asshown.Howmanydifferentweightobjectscanyouweighwiththesethree?

　　[Remembertheweightsmaybeplacedoneitherside]

答案详见第二页