PP-DS2完整详解版-V1.2

1PP-DataSufficiency2(DS2)完整詳解版V1.2作者:larry.twHuangHsin-YiPendaEngedimauricewpauline_chiouwilliam0625abc123ruru.lu備註：本版權內容歸作者和論壇共有，嚴禁任何未經允許的商業使用。2RevisedHistory由於這是眾人一起完成的,難免會有疏失,希望大家可以一起修正錯誤,讓這份詳解變得更完整!版本增加規則如下:1)修正算式錯誤or提出更好的算法,請把版本小數+1(Ex:V1.0-V1.1)2)增加or補齊題目,請把版本個位數+1(Ex:V2.0-V3.0)版本修正內容(請標題號)作者日期V1.0新增全部詳解(Q1~Q218)larry.twHuangHsin-YiPendaEngedimauricewpauline_chiouwilliam0625abc123ruru.lu2008/7/17V1.1UpdateQ109,Q174larry.tw2008/8/29V1.2UpdateQ68,Q135,Q155,Q184,Q192larry.twPhilosophia2008/11/103PracticeTest#2DataSufficiency(218Questions)1.86-!-item-!-187;#058&000060Ismk?(1)3m3k(2)2m2k--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】D【思路】(1)把3約掉,mk,充分(2)把2約掉,mk,充分--------------------------------------------------------------------------------------------------------------------------------------------------------2.140-!-item-!-187;#058&000076Ifkisapositiveinteger,iskthesquareofaninteger?(1)kisdivisibleby4.(2)kisdivisiblebyexactlyfourdifferentprimenumbers.--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】E【思路】問K是一個整數的平方嗎?(1)舉例k=16=24是整數的平方,k=4x3不是整數的平方,所以不確定,不充分(2)k=2x3x5x7K不是整數的平方K=22222357K是整數的平方,也不確定,所以不充分(1)+(2)K=22222357K可被四除,也被四個不同的質數除,K會是整數的平方k=22357K可被四除,也被四個不同的質數除,但K不能整數的平方,所以還是不充分!--------------------------------------------------------------------------------------------------------------------------------------------------------3.195-!-item-!-187;#058&000100Ifwandzarepositive,iszw1?(1)wz(2)z4--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】A【思路】因為z是正數,所以題目可改寫wz?(1)確定充分(2)不知w,不充分--------------------------------------------------------------------------------------------------------------------------------------------------------4.300-!-item-!-187;#058&000133Thesalepriceofacertainjacketwas15percentlessthanitsoriginalprice,andthesalepriceofacertainshirtwas10percentlessthanitsoriginalprice.Howmuchgreaterwastheoriginalpriceofthejacketthantheoriginalpriceoftheshirt?(1)Thesalepriceofthejacketwas$83greaterthanthesalepriceoftheshirt.(2)Theoriginalpriceofthejacketwas$140.--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】C【思路】依題意設SalespriceJacket=Sj4OriginalpriceJacketOjSalespriceshirt=SsOriginalpriceshirt=Os題目給的條件85100SjOj,90100SsOs題目問Oj–Os=?(1)Sj=83+Ss,四個未知數,只有三個方程式,無法算出,不充分(2)Oj=140,四個未知數,只有三個方程式,無法算出,不充分(1)+(2)四個未知數,有四個方程式,可解,充分!--------------------------------------------------------------------------------------------------------------------------------------------------------5.354-!-item-!-187;#058&000214Ifx,y,andzareintegers,isx+y+2zeven?(1)x+ziseven.(2)y+ziseven.--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】C【思路】題目問x+y+2z=2k(K是整數)?(1)x+z=2k(K是整數),不知y,不充分(2)y+z=2k(K是整數),不知x,不充分(1)+(2)將(1)(2)的式子加起來等於x+y+2z=4k(K是整數),確定是偶數,充分--------------------------------------------------------------------------------------------------------------------------------------------------------6.408-!-item-!-187;#058&000218Theoperation@representseitheraddition,subtraction,ormultiplicationofintegers.Whatisthevalueof1@0?(1)0@2=2(2)2@0=2--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】D【思路】(1)@=+,只有+才有可能,代回1@0,得知答案為1,充分(2)@=+or-,代回1@0,答案唯一,充分--------------------------------------------------------------------------------------------------------------------------------------------------------7.462-!-item-!-187;#058&000279OnekilogramofacertaincoffeeblendconsistsofxkilogramoftypeIcoffeeandykilogramoftypeIIcoffee.ThecostoftheblendisCdollarsperkilogram,whereC=6.5x+8.5y.Isx0.8?(1)y0.15(2)C7.30--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】B【思路】這邊題目中OnekilogramofacertaincoffeeblendconsistsofxkilogramoftypeIcoffeeandykilogramoftypeIIcoffee暗藏方程式,容易忽略x+y=1(1)設y=1-x,則1-x0.15x0.85,可能小於或大於0.8,所以不充分!(2)設y=1-x代入C7.306.5x+8.5y7.306.5x+8.5(1-x)7.30簡化式子後可得x0.6,確定小於0.8,充分--------------------------------------------------------------------------------------------------------------------------------------------------------58.563-!-item-!-187;#058&000288Ifnandpareintegers,isp0?(1)n+10(2)np0--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】C【思路】(1)n-1,不知P值,不充分(2)np相乘大於0,表示同號(++或--),一樣不知P,不充分(1)+(2)n-1表示n是正號(不能為0,如果是0的話,第二個式子就不成立了)所以p要跟n同號,也是正號,確定0,充分----------