算术题是GRE数学考试中的常见题型，下面就分析一些简单的数学题
41.At College C there are from 2 to 4 introductory philosophy classes each semester, and each of these classes has from 20 to 30 students enrolled. If one semester 10 percent of the students enrolled in introductory philosophy failed, what is the greatest possible number who failed? A.12 B.10 C.8 D.6 E.3 答案：A 42.In each of the years 1983 and 1984, the total number of automobiles sold in the United States was 1.2 million more than in the previous year. Percent increase in the number of automobiles sold in 1983 over 1982 Percent increase in the number of automobiles sold in 1984 over 1983 答案：A 43.A school district has 1989 computers, which is approximately one computer for every 68.6 students. Of the following, which is the closest approximation, in thousands, of the number of students in the school district? A.30 B.120 C.140 D.160 E.200 答案：C 44.If the sum of five consecutive even integers is 70, what is the value of the greatest of the five integers. A.12 B.14 C.18 D.20 E.22 答案：C 45.The sum of the first 50 positive integers is 1275. What is the sum of the integers from 51 to 100, inclusive? A.2525 B.2550 C.325 D.3775 E.5050 答案：D 46.The numbers in a table are arranged in 10 rows and 4 columns such that one number is placed at the intersection of each row and column. How many numbers are contained in the table、 A.14 B.40 C.400 D.104 E.410 答案：B 47.In how many of the integers between 1 and 100 does the digit 5 occur exactly once? A.10 B.18 C.19 D.20 E.21 答案：B 48.If n is any prime number greater than 2, which of the following cannot be a prime number? A.n-4 B.n-3 C.n-1 D.n+2 E.n+5 答案：E 49.If the range of the six measurements 140, 125, 180, 110, 165, and x is 80, which of the following could be the value of x? A.60 B.85 C.190 D.220 E.245 答案:C 50.The 10 households on a certain street have household incomes that range from $34,000 to $150,000 and an average