2025年GMAT专项训练试卷及答案

2025年GMAT专项训练试卷及答案考试时间：______分钟总分：______分姓名：______Section1:ReadingComprehensionPassage1Theproliferationofdigitalinformationhasfundamentallyalteredthelandscapeofknowledgeacquisitioninthe21stcentury.Unlikethepast,wheninformationwasoftenguardedbyinstitutionsorconfinedtophysicallibraries,theinternethasdemocratizedaccesstodataonanunprecedentedscale.Thisshiftofferssignificantadvantages,particularlyinfosteringresearchandlearningacrossdiversefields.Scholarscannowquicklyaccessscholarlypapers,historicaldocuments,andscientificdatafromaroundtheglobe,potentiallyacceleratingthepaceofdiscovery.However,thiseaseofaccessalsopresentsconsiderablechallenges.Thesheervolumeofavailableinformationcanbeoverwhelming,makingitdifficultforuserstodiscerncrediblesourcesfromdubiousones.Furthermore,thespeedatwhichinformationspreadsonlineoftenprecedesitsverification,leadingtotherapiddisseminationofmisinformationorunsubstantiatedclaims.Thisphenomenonposesaseriousthreattoinformeddiscourseandcanunderminepublictrustinscientificandhistoricalnarratives.1.Accordingtothepassage,onemajoradvantageofdigitalinformationisitspotentialto:(A)Reducethecostofphysicalinfrastructureforstoringdata.(B)Increasethespeedatwhichresearchprojectscanbecompleted.(C)Centralizeallglobalknowledgeintoasingle,easilysearchabledatabase.(D)Makespecializedknowledgemoreaccessibletoindividualswithoutinstitutionalaffiliation.(E)Decreasethetimerequiredforscholarstopublishtheirfindings.2.Thepassagesuggeststhattheproliferationofdigitalinformationcreatesachallengerelatedto:(A)Thephysicalsecurityoflibrariesandarchives.(B)Thepotentialforinformationoverloadandthedifficultyinverifyingsources.(C)Theeconomicviabilityofonlineplatformshostingdigitalcontent.(D)Thepreservationofhistoricaldocumentsindigitalformat.(E)Therateatwhichnewtechnologiesaredeveloped.3.Theword"democratized"inthefirstparagraphisbestdescribedas:(A)Restricted(B)Restrictedandcontrolled(C)Madeaccessibletoawiderpopulation(D)Madelessrelevant(E)Madeproprietary4.Thepassageimpliesthattherapiddisseminationofinformationonlinecanhavenegativeconsequences,suchas:(A)Slowingdowntherateofscientificdiscovery.(B)Increasingthecostofaccessingscholarlymaterials.(C)Underminingpublictrustandinformeddiscussion.(D)Reducingthediversityofavailableinformationsources.(E)Leadingtoincreasedcensorshipofonlinecontent.5.Theauthor'sprimarypurposeinthepassageisto:(A)Argueagainsttheuseofdigitalinformationinresearch.(B)Describethetechnologicalinfrastructurerequiredfordigitalinformationaccess.(C)Explainthebenefitsandchallengesofaccessinginformationinthedigitalage.(D)Advocateforgovernmentregulationofonlineinformation.(E)Comparetraditionallibrarieswithdigitaldatabases.Passage2Traditionalagriculturehaslongbeenreliantontheseasonalcyclesofnature,dictatingplanting,harvesting,andresourceallocation.However,theacceleratingeffectsofclimatechangeareincreasinglydisruptingthesepredictablepatterns,posingsignificantthreatstoagriculturalproductivityandfoodsecurityworldwide.Risingglobaltemperatures,alteredprecipitationpatterns,andtheincreasedfrequencyofextremeweathereventslikedroughtsandfloodsdirectlyimpactcropyields.Heatstresscanreducethequalityandquantityofharvests,whileirregularrainfallcanleadtobothwaterscarcityandwaterlogging,damagingcropsanddepletingsoilmoisture.Furthermore,thechangingclimatefacilitatesthespreadofplantdiseasesandpestsintonewregions,furthercomplicatingagriculturalmanagement.Thesechallengesarenotevenlydistributed;developingnations,whichoftenhavelessresilientagriculturalsystemsandfewerresourcestoadapt,areparticularlyvulnerabletotheseshifts,potentiallyexacerbatingglobalfoodinequality.6.Thepassageprimarilydiscussestheimpactofwhichfactorontraditionalagriculture?(A)Advancesinagriculturaltechnology.(B)Changesinglobaltradepolicies.(C)Thetransitionfrommanualtomechanicallabor.(D)Climatechangeanditsvariousmanifestations.(E)Theincreasingdemandfororganicfoodproducts.7.Accordingtothepassage,howarerisingglobaltemperaturesaffectingagriculture?(A)Theyareextendingthegrowingseasoninmanyregions.(B)Theyareprimarilyincreasingtheefficiencyofirrigationsystems.(C)Theyarecausingheatstressthatreducescropyieldsandquality.(D)Theyareleadingtoasignificantincreaseinsoilfertility.(E)Theyareencouragingthegrowthofpreviouslynon-existentcropvarieties.8.Theword"facilitates"inthesecondparagraphisclosestinmeaningto:(A)hinders(B)disrupts(C)enables(D)slowsdown(E)controls9.Thepassageindicatesthatdevelopingnationsareparticularlyvulnerabletoclimatechangeimpactsonagriculturebecause:(A)Theyoftenlackthetechnologytopredictweatherpatternsaccurately.(B)Theiragriculturalsystemsaretypicallylessdiversified.(C)Theyhavefewerresourcestoinvestinclimateadaptationmeasures.(D)Theirpopulationsaregenerallymoresusceptibletofoodborneillnesses.(E)Theyrelymoreheavilyonrain-fedagriculture.10.Whichofthefollowingstatementswouldtheauthormostlikelyagreewith?(A)Climatechangeprimarilyaffectsagriculturalproductivityindevelopedcountries.(B)Traditionalagriculturalpracticesareinherentlyincompatiblewithachangingclimate.(C)Thechallengesposedbyclimatechangetoagriculturecanbeeffectivelymanagedwithincreasedglobalcooperationandinvestment.(D)Theincreasedspreadofplantdiseasesisamoresignificantthreattoagriculturethanchangesinweatherpatterns.(E)Farmersindevelopingnationsshouldfocussolelyoncultivatingdrought-resistantcrops.Section2:SentenceCorrection11.Thecommittee,includingmemberswithexpertiseineconomicsandenvironmentalscience,meetseveryTuesdaytodiscussthepotentialimpactsofproposedlegislationonbothlocaleconomiesandnaturalresources.(A)Thecommittee,includingmemberswithexpertiseineconomicsandenvironmentalscience,meetseveryTuesdaytodiscussthepotentialimpactsofproposedlegislationonbothlocaleconomiesandnaturalresources.(B)Thecommittee,whichincludesmemberswithexpertiseineconomicsandenvironmentalscience,meetseveryTuesdaytodiscussthepotentialimpactsofproposedlegislationonbothlocaleconomiesandnaturalresources.(C)Thecommittee,madeupofmemberswithexpertiseineconomicsandenvironmentalscience,meetseveryTuesdaytodiscussthepotentialimpactsofproposedlegislationonbothlocaleconomiesandnaturalresources.(D)EveryTuesday,thecommittee,whichincludesmemberswithexpertiseineconomicsandenvironmentalscience,meetstodiscussthepotentialimpactsofproposedlegislationonbothlocaleconomiesandnaturalresources.(E)EveryTuesday,thecommitteemeets,includingmemberswithexpertiseineconomicsandenvironmentalscience,todiscussthepotentialimpactsofproposedlegislationonbothlocaleconomiesandnaturalresources.12.Duetoitscomplexnature,theprojectrequiredasignificantamountofresearchanddevelopmentbeforetheactualconstructionphasecouldbegin,whichinvolvedateamofengineersandarchitectsworkingcollaboratively.(A)Duetoitscomplexnature,theprojectrequiredasignificantamountofresearchanddevelopmentbeforetheactualconstructionphasecouldbegin,whichinvolvedateamofengineersandarchitectsworkingcollaboratively.(B)Theproject'scomplexnaturemeantthatasignificantamountofresearchanddevelopmentwasrequiredbeforetheactualconstructionphasecouldbegin,whichinvolvedateamofengineersandarchitectsworkingcollaboratively.(C)Becauseoftheproject'scomplexity,asignificantamountofresearchanddevelopmentwasrequiredbeforetheconstructionphasecouldbegin,involvingateamofengineersandarchitectsworkingcollaboratively.(D)Duetoitscomplexnature,asignificantamountofresearchanddevelopmentwasrequiredbytheprojectbeforetheactualconstructionphasecouldbegin,whichinvolvedacollaborativeeffortbetweenengineersandarchitects.(E)Theproject'scomplexitynecessitatedasignificantamountofresearchanddevelopmentpriortotheactualconstructionphase,whichrequiredthecollaborativeworkofengineersandarchitects.13.Sarahnotonlyhasastrongunderstandingofthelegalprinciplesinvolvedinthecasebutalsoeffectivelycommunicatesherarguments,whichhasearnedherrespectfromherpeersandjudgesalike.(A)Sarahnotonlyhasastrongunderstandingofthelegalprinciplesinvolvedinthecasebutalsoeffectivelycommunicatesherarguments,whichhasearnedherrespectfromherpeersandjudgesalike.(B)NotonlydoesSarahhaveastrongunderstandingofthelegalprinciplesinvolvedinthecasebutalsosheeffectivelycommunicatesherarguments,whichhasearnedherrespectfromherpeersandjudgesalike.(C)Sarahnotonlyhasastrongunderstandingofthelegalprinciplesinvolvedinthecasebutalsocommunicatesherargumentseffectively,earningherrespectfromherpeersandjudgesalike.(D)Sarahhasastrongunderstandingofthelegalprinciplesinvolvedinthecaseandalsocommunicatesherargumentseffectively,earningherrespectfromherpeersandjudgesalike.(E)Sarah'sstrongunderstandingofthelegalprinciplesinvolvedinthecase,alongwithhereffectivecommunicationofarguments,hasearnedherrespectfromherpeersandjudgesalike.14.Thecompany'sdecisiontoinvestheavilyinrenewableenergysourcesreflectsnotonlyacommitmenttoenvironmentalsustainabilitybutalsoacknowledgesthepotentiallong-termeconomicbenefitsfortheindustryanditsstakeholders.(A)Thecompany'sdecisiontoinvestheavilyinrenewableenergysourcesreflectsnotonlyacommitmenttoenvironmentalsustainabilitybutalsoacknowledgesthepotentiallong-termeconomicbenefitsfortheindustryanditsstakeholders.(B)Thecompany'sdecisiontoinvestheavilyinrenewableenergysourcesreflectsbothacommitmenttoenvironmentalsustainabilityandacknowledgesthepotentiallong-termeconomicbenefitsfortheindustryanditsstakeholders.(C)Thecompany'sinvestmentinrenewableenergysourcesreflectsnotonlyitscommitmenttoenvironmentalsustainabilitybutalsothepotentiallong-termeconomicbenefitsitacknowledgesfortheindustryanditsstakeholders.(D)Byinvestingheavilyinrenewableenergysources,thecompanyreflectsnotonlyitscommitmenttoenvironmentalsustainabilitybutalsoacknowledgesthepotentiallong-termeconomicbenefitsfortheindustryanditsstakeholders.(E)Thecompany'sheavyinvestmentinrenewableenergysourcesreflectsitscommitmenttoenvironmentalsustainabilityandalsoacknowledgesthepotentiallong-termeconomicbenefitsfortheindustryanditsstakeholders.15.Althoughtheinitialresultsoftheclinicaltrialappearedpromising,furtheranalysisrevealedthatthetreatment'seffectivenessmightbelimitedtoaspecificsubgroupofpatients,whichcallsformoreresearchbeforewidespreadimplementation.(A)Althoughtheinitialresultsoftheclinicaltrialappearedpromising,furtheranalysisrevealedthatthetreatment'seffectivenessmightbelimitedtoaspecificsubgroupofpatients,whichcallsformoreresearchbeforewidespreadimplementation.(B)Theinitialresultsoftheclinicaltrialappearedpromising,althoughfurtheranalysisrevealedthatthetreatment'seffectivenessmightbelimitedtoaspecificsubgroupofpatients,callingformoreresearchbeforewidespreadimplementation.(C)Althoughtheinitialresultsoftheclinicaltrialappearedpromising,furtheranalysisshowedthatthetreatment'seffectivenessmightbelimitedtoaspecificsubgroupofpatients,andthiscallsformoreresearchbeforewidespreadimplementation.(D)Theinitialresultsoftheclinicaltrialappearedpromising,butfurtheranalysisrevealedthatthetreatment'seffectivenessmightbelimitedtoaspecificsubgroupofpatients,whichcallsformoreresearchpriortowidespreadimplementation.(E)Theinitialresultsoftheclinicaltrialappearingpromising,furtheranalysisrevealedthatthetreatment'seffectivenessmightbelimitedtoaspecificsubgroupofpatients,andthisnecessitatesmoreresearchbeforewidespreadimplementation.Section3:CriticalReasoning16.ThegovernmentofCountryXrecentlyimplementedanewpolicyrequiringallemployeesoflargecorporationstoreceivementalhealthdaysoffthroughouttheyear,inadditiontothestandardsickleave.Proponentsarguethatthispolicywillsignificantlyimproveemployeewell-beingandreducestress-relatedabsenteeism.ApreliminaryreportbytheMinistryofLaborsuggestsacorrelationbetweentheimplementationofthispolicyanda15%decreaseinoverallemployeeabsenteeismacrossmajorcorporationswithinthefirstquarter.Basedonthisreport,thegovernmentconcludesthatthenewmentalhealthdayspolicyiseffectiveinreducingabsenteeism.*Whichofthefollowing,iftrue,moststrengthenstheargumentmadebythegovernment?(A)Corporationsthatimplementedthepolicyalsoinvestedheavilyinon-sitefitnesscentersandwellnessprograms.(B)Theaveragenumberofsickdaystakenbyemployeesfornon-stressrelatedillnessesremainedconstantduringthefirstquarter.(C)Employeesurveysindicatedthatalargemajorityofemployeesfeltthenewpolicyhelpedthemmanageworkstressmoreeffectively.(D)Beforethepolicy'simplementation,corporationswerealreadyofferingsubstantialpaidtimeofftotheiremployees.(E)The15%decreaseinabsenteeismoccurredprimarilyinindustrieswithtraditionallyhighemployeeturnoverrates.17.Aprominentnutritionisthasarguedagainsttheconsumptionofrefinedsugars,claimingthattheyareaprimarycontributortorisingobesityratesglobally.Hermainevidenceisastatisticalcorrelationshowingthatcountrieswithhigherpercapitaconsumptionofrefinedsugarsalsotendtohavehigherobesityrates.Criticspointoutthatthiscorrelationdoesnotimplycausation,andtheysuggestthatotherfactors,suchassedentarylifestylespromotedbyurbanizationortheavailabilityofaffordablehigh-caloriefoods,couldequallyexplaintheobservedtrend.*Thecritics'mainargumentreliesonwhichofthefollowing?(A)Challengingthestatisticalaccuracyofthenutritionist'sdata.(B)Providinganalternativeexplanationfortheobservedcorrelationbetweensugarconsumptionandobesityrates.(C)Questioningthenutritionist'squalificationsandexpertiseinglobalhealth.(D)Arguingthatrefinedsugarsarenotasharmfulasthenutritionistclaims.(E)Suggestingthatthenutritionist'sargumentisbasedonanecdotalevidenceratherthanscientificresearch.18.Acitycouncilisconsideringwhethertoapprovetheconstructionofanewsportscomplex.Akeyargumentinfavoroftheprojectisthatitwillcreatehundredsoftemporaryconstructionjobsandprovidealong-termvenueforcommunitysportsactivities,therebyboostinglocaltourism.Opponentsarguethatthelong-termeconomicbenefitsareuncertainandthattheprojectwillsignificantlyincreasetrafficcongestionandpropertytaxesinthesurroundingarea.Afeasibilitystudycommissionedbythecitypredictsanetpositiveeconomicimpactovera10-yearperiod,primarilyduetoincreasedtourismandtaxrevenuefromthesportscomplexanditsvisitors.*Thefeasibilitystudy'spredictionofanetpositiveeconomicimpactreliesonwhichofthefollowingassumptions?(A)Theconstructionjobscreatedwillprimarilygotolocalresidentswhowillspendtheirearningswithinthecity.(B)Theincreaseinpropertytaxeswillbeoffsetbyotherreductionsinthecity'staxbudget.(C)Thesportscomplexwillattractasufficientnumberoftouriststogeneratesignificantadditionalspending.(D)Theincreaseintrafficcongestionwillbeminimalandeasilymanagedbythecity'sinfrastructure.(E)Thelong-termmaintenancecostsofthesportscomplexwillbelowerthaninitiallyprojected.19.Apharmaceuticalcompanydevelopedanewdrugintendedtolowerbloodpressure.InaPhaseIIIclinicaltrialinvolving1,000patientswithhypertension,thedrugwasfoundtobeeffectiveinloweringsystolicbloodpressurebyanaverageof10pointscomparedtoaplacebogroup,althoughthereductionwasnotstatisticallysignificantfordiastolicbloodpressure.Thecompanyplanstomarketthedrugspecificallyforpatientswithhighsystolicbloodpressure.*Whichofthefollowing,iftrue,mostseriouslyquestionsthecompany'splantomarketthedrugbasedontheresultsoftheclinicaltrial?(A)Thesideeffectsofthedrugareminimalandeasilymanageable.(B)Previousstudieshaveshownthatlifestylechangescanalsoeffectivelylowersystolicbloodpressure.(C)Theplaceboeffectwassignificantintheclinicaltrial,potentiallymaskingthedrug'strueefficacy.(D)Thepatientpopulationintheclinicaltrialmaynotberepresentativeofthebroaderpopulationwithhypertension.(E)Thedrugissignificantlycheaperthanexistingtreatmentsforhighbloodpressure.20.Alocalnewspaperreportedthatthenumberofstudentsenrollinginonlinecoursesofferedbythecity'scommunitycollegehasdoubledoverthepastyear.Thereportattributesthisincreaseprimarilytotheconvenienceandflexibilityoftakingcoursesonline,allowingstudentstolearnattheirownpaceandschedule.Thecollegeadministration,however,notesthattheyhavealsosignificantlyexpandedtheironlinecourseofferingsduringthisperiod,addingdozensofnewcoursesinhigh-demandfields.*Whichofthefollowing,iftrue,wouldmosthelptoexplainthedoublingofonlinestudentenrollments,takingintoaccountboththestudents'preferencesandthecollege'sactions?(A)Thecostofonlinecoursesatthecommunitycollegehasremainedthesameastraditionalcourses.(B)ManystudentswhopreviouslyattendedtraditionalcourseshaveswitchedtoonlineformatsduetotheCOVID-19pandemic.(C)Thecollegehasinvestedinimprovingthequalityandinteractivityofitsonlinecourses.(D)Onlinestudentshavereportedhighercompletionratescomparedtotraditionalstudents.(E)Aneighboringuniversity,whichpreviouslyofferedcompetingonlinecourses,ceaseditsonlineprogram.Section4:ProblemSolving21.Ifxandyareintegerssuchthatx>y,andtheproductxyisnegative,whichofthefollowingmustbetrue?(A)x+yispositive.(B)x+yisnegative.(C)x-yispositive.(D)x-yisnegative.(E)x/yisnegative.22.AtraintravelsfromStationAtoStationBataconstantspeedof60milesperhour.Ifthetrainmakesa20-minutestopatStationB,andthentravelsbacktoStationAataconstantspeedof40milesperhour,whatistheaveragespeedoftheentiretrip(inmilesperhour)?(A)40(B)45(C)48(D)50(E)5223.Inacertainsequence,thetermanisdefinedbytheformulaan=2n-3forallpositiveintegersn.Whatisthevalueofa10+a11+a12?(A)27(B)30(C)33(D)36(E)3924.Arectanglehasaperimeterof30inches.Ifthewidthoftherectangleis5inches,whatistheareaoftherectangle(insquareinches)?(A)50(B)75(C)100(D)125(E)15025.If5x-7=3x+9,whatisthevalueof2x?(A)2(B)4(C)6(D)8(E)1026.Aboxcontains3redballs,4blueballs,and5greenballs.Iftwoballsaredrawnatrandomwithoutreplacement,whatistheprobabilitythatbothballsareofthesamecolor?(A)1/22(B)3/22(C)1/4(D)1/3(E)2/1127.IntriangleABC,angleAmeasures45degrees,angleBmeasures60degrees,andsideACis10inches.WhatisthelengthofsideAB(ininches)?(A)5√2(B)5√3(C)10√2(D)10√3(E)20√328.Iff(x)=x²-4x+3,whatisthevalueoff(2)?(A)-1(B)0(C)1(D)3(E)529.Acirclehasanareaof25πsquareunits.Whatistheapproximatelengthofthecircle'scircumference(inunits)?(A)10(B)15(C)20(D)25(E)3030.Aninvestmentof$1,000earnsinterestatarateof5%peryear,compoundedannually.After3years,howmuchinterest(indollars)hastheinvestmentearned?(A)150(B)157.63(C)157.50(D)165.00(E)175.00Section5:ProblemSolving31.Ifaandbarepositiveintegerssuchthata/b=3.5,whatisthesmallestpossiblevalueofa+b?(A)8(B)9(C)10(D)12(E)1432.Aregularhexagonhasaperimeterof42inches.Whatisthelengthofoneofitsdiagonals(ininches)?(A)7(B)7√2(C)7√3(D)14(E)14√333.Inacertainsequence,thetermanisdefinedrecursivelybytheformulaa1=1andan=an-1+5forn>1.Whatisthevalueofa10?(A)44(B)49(C)54(D)59(E)6434.Acylindricaltankhasaradiusof3feetandaheightof5feet.Ifthetankisfilledwithwatertoaheightof4feet,whatisthevolumeofthewaterinthetank(incubicfeet)?(A)28.27(B)37.68(C)42.39(D)56.55(E)113.1035.Ifx²-5x+6=0,whatisthesumoftherootsofthisequation?(A)-5(B)-3(C)3(D)5(E)636.Astoreishavingasale,offeringa20%discountonallitems.Ifacustomerbuysanitemwithaoriginalpriceof$80,howmuchwillthecustomerpayafterthediscount?(A)$16(B)$64(C)$64.80(D)$80(E)$9637.Inatriangle,thelengthsofthetwoshortersidesare5inchesand7inches.Whichofthefollowingcanbethelengthofthelongestside(ininches)?(A)2(B)6(C)8(D)12(E)1538.Iff(x)=|x-3|,whatisthevalueoff(0)+f(4)?(A)1(B)3(C)4(D)7(E)839.Abagcontains4redmarbles,6bluemarbles,and5greenmarbles.Ifonemarbleisdrawnatrandomfromthebag,whatistheprobabilitythatthemarbleisnotblue?(A)1/3(B)2/5(C)3/5(D)2/3(E)3/440.Theaverageof5numbersis15.Ifoneofthenumbersisremoved,theaverageoftheremainingnumbersbecomes14.Whatwasthevalueoftheremovednumber?(A)10(B)12(C)14(D)15(E)16Section6:ProblemSolving41.Asequenceisdefinedbytheformulaan=n(n+1)/2forallpositiveintegersn.Whatisthevalueofa10?(A)45(B)55(C)55(D)90(E)10042.Inarighttriangle,thelengthsofthetwolegsare6inchesand8inches.Whatisthelengthofthehypotenuse(ininches)?(A)10(B)12(C)14(D)15(E)2843.If3x+4y=14and2x-3y=5,whatisthevalueofx?(A)1(B)2(C)3(D)4(E)544.Arectangularfieldhasalengththatis3timesitswidth.Iftheperimeterofthefieldis100meters,whatistheareaofthefield(insquaremeters)?(A)300(B)400(C)600(D)900(E)120045.Iff(x)=2x²-4x+1,whatisthevalueoff(-1)?(A)-1(B)1(C)3(D)5(E)746.Amixturecontainsalcoholandwaterintheratio2:5.If10litersofwaterareaddedtothemixture,thenewratioofalcoholtowaterbecomes1:4.Whatwastheoriginalvolumeofthemixture(inliters)?(A)20(B)25(C)30(D)35(E)4047.Acirclehasaradiusof4inches.Whatistheareaofthecircle(insquareinches)?(A)8π(B)16π(C)24π(D)32π(E)36π48.Ifa=2andb=-3,whatisthevalueofa²+b²?(A)-5(B)1(C)5(D)10(E)1149.Anitemisoriginallypricedat$120.Itisfirstdiscountedby20%,andthenthediscountedpriceisfurtherdiscountedby30%.Whatisthefinalpriceoftheitem(indollars)?(A)72(B)78(C)80(D)96(E)10050.Thesumofthefirst20positiveintegersis210.Whatisthesumoftheintegersfrom21to40inclusive?(A)400(B)410(C)420(D)430(E)440Section7:CriticalReasoning51.Anewstudyclaimsthataspecificvitaminsupplementcansignificantlyimprovememoryrecallinelderlypatients.Thestudyinvolved100participantsovertheageof65whotookthevitaminsupplementdailyforthreemonths,whileacontrolgroupof100similarparticipantstookaplacebo.Theresultsshowedastatisticallysignificantimprovementinmemorytestscoresforthesupplementgroupcomparedtothecontrolgroup.Basedonthesefindings,theresearchersconcludethatthevitaminsupplementisaneffectivewaytoenhancememoryintheelderly.*Whichofthefollowing,iftrue,moststrengthenstheconclusiondrawnbytheresearchers?(A)Theparticipantsinthestudywereallhealthyandactivebeforestartingthesupplementorplacebo.(B)Thememorytestusedinthestudywasdesignedtomeasurelong-termrecallspecifically.(C)Theparticipantsinthesupplementgroupwereunawarethattheywerereceivingtheactualsupplement.(D)Thecontrolgroupparticipantsexperiencedaslightdeclineinmemoryscoresoverthethreemonths.(E)Previousresearchhassuggestedthatcertainlifestylefactors,suchasexercise,canalsoimprovememoryrecall.52.ThemanagementofCompanyXdecidedtoimplementanewperformanceappraisalsystem,whichfocusesheavilyonquantitativemetricsratherthanqualitativefeedback.Therationalebehindthischangewasthattheoldsystemwasperceivedasbeingtoosubjectiveandunfair,leadingtodecreasedemployeemoraleandmotivation.However,asurveyconductedonemonthaftertheimplementationshowedthatemployeemoralehadactuallydecreasedfurther,whilemotivationremainedunchanged.*Themanagement'sdecisiontoimplementthenewperformanceappraisalsystemisbasedonwhichofthefollowingassumptions?(A)Quantitativemetricsarealwaysmorereliablethanqualitativefeedbackinevaluatinge