几道GRE数学题
1.In a series of races,10 toys cars are raced,2 cars at a time.If
each car must race each of the other cars exactly twice,how many races must be held?
2.The daily rate for a hotel room that sleeps 4 people is $39 for one person
and x dollars for each additional person.If 3 people take the room for one day
and each pays $21 for the room,what is the value of
3.What fraction of the positive intergers that are multiples of 30 and are less than or equal to 360 are multiples of 12?
答案为1/2