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GRE Math: Common Errors

Subjects : gre, math

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Describe the relationship between 3x^2 and 3(x - 1)^2
$11 -448
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
31 - 37
(n-2) x 180

2. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
10! / 3!(10-3)! = 120
28. n = 8 - k = 2. n! / k!(n-k)!
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
True

3. How to determine percent decrease?
4725
(amount of decrease/original price) x 100%
28. n = 8 - k = 2. n! / k!(n-k)!
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

4. What are complementary angles?
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
A subset.
The set of elements which can be found in either A or B.
Two angles whose sum is 90.

5. In a regular polygon with n sides - the formula for the sum of interior angles
(n-2) x 180
1
The set of input values for a function.
The curve opens downward and the vertex is the maximum point on the graph.

6. What is the ratio of the surface area of a cube with an edge of 10 to the surface area of a rectangular solid with dimensions 2 - 4 - and 6?
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
N! / (k!)(n-k)!
3 - -3
75:11

7. If 10800 is invested at a simple interest rate of 4% - what is the value of the investment after 18 months?
Part = Percent X Whole
$11 -448
500
x^(4+7) = x^11

8. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
I
y = 2x^2 - 3
True
Cd

9. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
16.6666%
4725
67 - 71 - 73
6

10. Hector invested $6000. Part was invested in account with 9% simple annual interest - and the rest in account with 7% simple annual interest. If he earned $490 in the first year of these investments - how much did he invest in each account?
A reflection about the origin.
6 : 1 : 2
$3 -500 in the 9% and $2 -500 in the 7%.
10

11. Define an 'expression'.
4:5
II
An algebraic expression is a combination of one of more terms. Terms in an expression are separated by either addition or subtraction signs. (3xy - 4ab - -5cd - x^2 + x - 1)
5 OR -5

12. (-1)^2 =
13pi / 2
12.5%
1
C = (pi)d

13. Suppose that the graph of f(x) is the result of stretching y=x + 5 away from the x-axis by a factor of 2. What is the new equation for the graph f(x)?
62.5%
y = (x + 5)/2
180 degrees
7 / 1000

14. 60 < all primes <70
61 - 67
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
12sqrt2
(a - b)(a + b)

15. 70 < all primes< 80
71 - 73 - 79
Even
x^(4+7) = x^11
53 - 59

16. What is the graph of f(x) shifted upward c units or spaces?
1/(x^y)
N! / (n-k)!
F(x) + c
Ax^2 + bx + c where a -b and c are constants and a /=0

17. What is the 'Solution' for a set of inequalities.
288 (8 9 4)
A reflection about the origin.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
The overlapping sections.

18. What is the name for a grouping of the members within a set based on a shared characteristic?
Angle/360 x 2(pi)r
3 - -3
A subset.
90

19. Ratio of ages of Anna and Emma is 3:5 and of Emma and Nicolas is 3:5. What is the ratio of Anna to Nicholas' ages?
9 : 25
The shortest arc between points A and B on a circle'S diameter.
The overlapping sections.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

20. There are 10 finalists for the school spelling bee. A first - second - and third place trophy will be awarded. How many different people can get the three prizes?
10! / 3!(10-3)! = 120
6
13
The steeper the slope.

21. A company places a 6-symbol code on each product. The code consists of the letter T - followed by 3 numerical digits - and then 2 consonants (Y is a conson). How many codes are possible?
A= I (1 + (r/c))^tC - where I is the investment - C is the number of times compounded annually - and t is the number of years.
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
2(pi)r^2 + 2(pi)rh
441000 = 1 10 10 10 21 * 21

22. What is the name of set with a number of elements which cannot be counted?
(a - b)(a + b)
An infinite set.
(amount of decrease/original price) x 100%
31 - 37

23. T or F? Given d -e &f =/ 0 - [(d^3)e(f^5)] / 2d(e^3) / [3(d^2)(e^3)(f^7)] / [6(e^5)(f^2)]?
An algebraic expression is a combination of one of more terms. Terms in an expression are separated by either addition or subtraction signs. (3xy - 4ab - -5cd - x^2 + x - 1)
True
A circle centered on the origin with radius 8.
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

24. If Madagascar'S exports totaled 1.3 billion in 2009 - and 4% came from China - what was the value in millions of the country'S exports to China?
500
I
52
13pi / 2

25. Suppose that the graph of f(x) is the result of sliding the graph of y=2x^2 down 3 units of spaces. What is the new equation?
y = 2x^2 - 3
The interesection of A and B.
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
The third side is greater than the difference and less than the sum.

26. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
A subset.
1
441000 = 1 10 10 10 21 * 21
The empty set - denoted by a circle with a diagonal through it.

27. What is an exterior angle?
An angle which is supplementary to an interior angle.
Factors are few - multiples are many.
... the square of the ratios of the corresponding sides.
Ax^2 + bx + c where a -b and c are constants and a /=0

28. To convert a decimal to a percent...
Undefined
Indeterminable.
...multiply by 100.
A reflection about the origin.

29. 6w^2 - w - 15 = 0
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
Angle/360 x (pi)r^2
3/2 - 5/3
Triangles with same measure and same side lengths.

30. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
An isosceles right triangle.
A tangent is a line that only touches one point on the circumference of a circle.
6
4a^2(b)

31. Volume for a cylinder?
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
23 - 29
x^(4+7) = x^11
Area of the base X height = (pi)hr^2

32. How many 3-digit positive integers are even and do not contain the digit 4?
6
All the numbers on the number line (negative - rational - irrational - decimal - integer). All the numbers on the GRE are real. (-2 - 1 - .25 - 1/2 - pi)
The curve opens upward and the vertex is the minimal point on the graph.
288 (8 9 4)

33. A number is divisible by 6 if...
Its divisible by 2 and by 3.
1
The set of elements which can be found in either A or B.
A reflection about the axis.

34. Circumference of a circle?
1
Diameter(Pi)
... the square of the ratios of the corresponding sides.
An expression with just one term (-6x - 2a^2)

35. If the two sides of a triangle are unequal then the longer side...
$3 -500 in the 9% and $2 -500 in the 7%.
Lies opposite the greater angle
F(x + c)
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.

36. 1/2 divided by 3/7 is the same as
1/2 times 7/3
The sum of its digits is divisible by 3.
A= I (1 + (r/c))^tC - where I is the investment - C is the number of times compounded annually - and t is the number of years.
Infinite.

37. Which quadrant is the upper left hand?
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
The set of elements which can be found in either A or B.
5 OR -5
II

38. What is the maximum value for the function g(x) = (-2x^2) -1?
Move the decimal point to the right x places
9 & 6/7
1
F(x) + c

39. What is the slope of a vertical line?

40. A cylinder has surface area 22pi. If the cylinder has a height of 10 - what is its radius?
...multiply by 100.
90
1
13pi / 2

41. Nine coins are tossed simultaneously. In how many of the outcomes will the fourth coin tossed show heads?
The second graph is less steep.
2^9 / 2 = 256
... the square of the ratios of the corresponding sides.
A set with no members - denoted by a circle with a diagonal through it.

42. a^0 =
The union of A and B.
(b + c)
1
Two equal sides and two equal angles.

43. Simplify (a^2 + b)^2 - (a^2 - b)^2
All the numbers on the number line (negative - rational - irrational - decimal - integer). All the numbers on the GRE are real. (-2 - 1 - .25 - 1/2 - pi)
8
4a^2(b)
180

44. x^6 / x^3
6
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
An isosceles right triangle.
x^(6-3) = x^3

45. Formula for the area of a circle?
A = pi(r^2)
All the numbers on the number line (negative - rational - irrational - decimal - integer). All the numbers on the GRE are real. (-2 - 1 - .25 - 1/2 - pi)
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
The set of output values for a function.

46. Which is greater? 27^(-4) or 9^(-8)
The greatest value minus the smallest.
3/2 - 5/3
27^(-4)
Area of the base X height = (pi)hr^2

47. What is the formula for computing simple interest?
All the numbers on the number line (negative - rational - irrational - decimal - integer). All the numbers on the GRE are real. (-2 - 1 - .25 - 1/2 - pi)
16.6666%
A = I (1 + rt)
1

48. Formula to calculate arc length?
The greatest value minus the smallest.
441000 = 1 10 10 10 21 * 21
Arc length = (n/360) x pi(2r) where n is the number of degrees.
0

49. 1/8 in percent?
1
All the numbers on the number line (negative - rational - irrational - decimal - integer). All the numbers on the GRE are real. (-2 - 1 - .25 - 1/2 - pi)
75:11
12.5%

50. What is the side length of an equilateral triangle with altitude 6?
The overlapping sections.
4sqrt3. The triangle can be divided into two equal 30-60-90 triangles with side 6 as the side in which 6 = xsqrt3. So x =2sqrt3...
y = 2x^2 - 3
(a + b)^2