几道GRE数学题
1.Inaseriesofraces,10toyscarsareraced,2carsatatime.If
eachcarmustraceeachoftheothercarsexactlytwice,howmanyracesmustbeheld?
2.Thedailyrateforahotelroomthatsleeps4peopleis$39foroneperson
andxdollarsforeachadditionalperson.If3peopletaketheroomforoneday
andeachpays$21fortheroom,whatisthevalueof
3.Whatfractionofthepositiveintergersthataremultiplesof30andarelessthanorequalto360aremultiplesof12?
答案为1/2