真题汇总:2009年12月16日美国GRE数学真题部分

　　Wednesday, December 16, 2009

　　1. If (a)^(-3) + (b)^(-3) = 0 and ab is not equal to zero, then what is the value of (a/b)^2?

　　2. Col A: The number of ways of forming different groups of 2 kittens each from 8 kittens

　　Col B: The number of ways of forming different groups of 6 kittens each from 8 kittens

　　3. Col A: sqrt (120) + sqrt (50)

　　Col B: sqrt (90) + sqrt (80)

　　4. Given x is not equal to 0, y is not equal to 0 and xy is not equal to 0.

　　Col A: 1/(x^3+y^3)

　　Col B: 1/(x+y)^3

　　5. Given a line equation y = ax+b. If x-intercept is 5 and slope is 2, then

　　Col A: y-intercept

　　Col B: -10

　　6. Given a set of numbers: {10, 11, 12, 15, 15, 15, 17, 19, 20, 20}. If a number 15 is included in the series, then which of the following will change?

　　A. Mean

　　B. Median

　　C. Mode

　　D. Standard deviation

　　E. None

　　7. Given total(t) = n * p. If 'p' is reduced by 20%, then by what percentage, 'n' should be increased to balance the total?

　　9. In a set of five consecutive numbers, if the 美国GREatest value is x + 5, then what is the least value?

　　10. Given two concentric circles. The inner circle is a garden of radius 6m and the outer circle which has a cement path around the garden has a radius 8m. If the width of cement is 0.06, what is the volume of the cement?

　　(Similar to this)

　　11. Given statistics of bike sales in a company. In 1992, there is a loss of $600 and in 1993 there is a profit of $100. If in 1992, 3 million bikes were sold and in 1993, 4 million bikes were sold, then what is the net profit?