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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. What is the graph of f(x) shifted upward c units or spaces?
13
An isosceles right triangle.
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
F(x) + c

2. What is a finite set?
Its last two digits are divisible by 4.
The set of elements which can be found in either A or B.
83.333%
A set with a number of elements which can be counted.

3. Simplify the expression (p^2 - q^2)/ -5(q - p)
(n-2) x 180
(p + q)/5
1
13

4. To convert a decimal to a percent...
...multiply by 100.
A term is a numerical constant or the product (or quotient) of a numerical constant and one or more variables. (3x - 4x^2 and 2a/c)
C = (pi)d
1 & 37/132

5. 10<all primes<20
0
11 - 13 - 17 - 19
No - only like radicals can be added.
Its divisible by 2 and by 3.

6. x^6 / x^3
The sum of its digits is divisible by 3.
x^(6-3) = x^3
1.0843 X 10^11
6 : 1 : 2

7. 50 < all primes< 60
2.592 kg
53 - 59
23 - 29
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a

8. What is the empty set?
A set with no members - denoted by a circle with a diagonal through it.
A set with a number of elements which can be counted.
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
A circle centered at -2 - -2 with radius 3.

9. What is a central angle?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
... the square of the ratios of the corresponding sides.
4a^2(b)
A central angle is an angle formed by 2 radii.

10. A number is divisible by 6 if...
The objects within a set.
A reflection about the origin.
55%
Its divisible by 2 and by 3.

11. Number of degrees in a triangle
3
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
180
N! / (k!)(n-k)!

12. What are the members or elements of a set?
48
90pi
The objects within a set.
1

13. How to determine percent increase?
1/(x^y)
A = pi(r^2)
Ax^2 + bx + c where a -b and c are constants and a /=0
(amount of increase/original price) x 100%

14. What does scientific notation mean?
52
IV
A chord is a line segment joining two points on a circle.
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.

15. What is the ratio of the sides of an isosceles right triangle?
The set of elements which can be found in either A or B.
y = 2x^2 - 3
1:1:sqrt2
Arc length = (n/360) x pi(2r) where n is the number of degrees.

16. Is 0 even or odd?
Even
The sum of digits is divisible by 9.
10
Ax^2 + bx + c where a -b and c are constants and a /=0

17. If 10800 is invested at a simple interest rate of 4% - what is the value of the investment after 18 months?
C = 2(pi)r
$11 -448
1/2 times 7/3
Two angles whose sum is 90.

18. 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?
The sum of digits is divisible by 9.
75:11
The greatest value minus the smallest.
3/2 - 5/3

19. What is a major arc?

20. What is a set with no members called?
7 / 1000
.0004809 X 10^11
The empty set - denoted by a circle with a diagonal through it.
2 & 3/7

21. Which is greater? 200x^295 or 10x^294?
Ax^2 + bx + c where a -b and c are constants and a /=0
The union of A and B.
Relationship cannot be determined (what if x is negative?)
A circle centered at -2 - -2 with radius 3.

22. What is the sum of the angles of a triangle?
5
A circle centered at -2 - -2 with radius 3.
180 degrees
(amount of increase/original price) x 100%

23. What is the ratio of the sides of a 30-60-90 triangle?
27^(-4)
$3 -500 in the 9% and $2 -500 in the 7%.
1:sqrt3:2
Yes. [i.e. f(x) = x^2 - 1

24. What is the set of elements which can be found in either A or B?
The union of A and B.
An arc is a portion of a circumference of a circle.
A reflection about the origin.
10

25. What is the percent formula?
16.6666%
A reflection about the axis.
Part = Percent X Whole
1/a^6

26. a^2 - 2ab + b^2
3
(a - b)^2
4a^2(b)
Its last two digits are divisible by 4.

27. What are complementary angles?
Arc length = (n/360) x pi(2r) where n is the number of degrees.
Two angles whose sum is 90.
An angle which is supplementary to an interior angle.
A 30-60-90 triangle.

28. What is a tangent?
Sqrt 12
All numbers multiples of 1.
A tangent is a line that only touches one point on the circumference of a circle.
12.5%

29. In a triangle where the two legs are 4 and 3 - what is the value of a line directly intersecting the middle coming from the meeting point of the two legs?
A term is a numerical constant or the product (or quotient) of a numerical constant and one or more variables. (3x - 4x^2 and 2a/c)
A grouping of the members within a set based on a shared characteristic.
Its last two digits are divisible by 4.
2.4. We calculate the area (6) and then turn the triangle on its side and use x as the height to calculate again. (5x)/2=6

30. The larger the absolute value of the slope...
3
27^(-4)
The steeper the slope.
6 : 1 : 2

31. Suppose you have a set of n objects - and you want to select k of them - but the order doesn'T matter. What formula do you use to determine the number of combinations of n objects taken k at a time?
A reflection about the axis.
1:sqrt3:2
3 - -3
N! / (k!)(n-k)!

32. x^2 = 9. What is the value of x?
13pi / 2
The third side is greater than the difference and less than the sum.
1
3 - -3

33. Max and Min lengths for a side of a triangle?
2(pi)r^2 + 2(pi)rh
16.6666%
180 degrees
The third side is greater than the difference and less than the sum.

34. 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?
52
N! / (k!)(n-k)!
The sum of digits is divisible by 9.
A central angle is an angle formed by 2 radii.

35. If an inequality is multiplied or divided by a negative number....
6 : 1 : 2
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
1
The direction of the inequality is reversed.

36. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
Two angles whose sum is 90.
28. n = 8 - k = 2. n! / k!(n-k)!
The shortest arc between points A and B on a circle'S diameter.
N! / (n-k)!

37. 1/2 divided by 3/7 is the same as
Pi is the ratio of a circle'S circumference to its diameter.
75:11
4725
1/2 times 7/3

38. 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?
70
9 : 25
180
Its divisible by 2 and by 3.

39. Circumference of a circle?
Diameter(Pi)
Indeterminable.
The set of elements found in both A and B.
71 - 73 - 79

40. 25^(1/2) or sqrt. 25 =
5 OR -5
1
1/a^6
288 (8 9 4)

41. If r - t - s & u are distinct - consecutive prime numbers - less than 31 - which of the following could be an average of them (4 - 4.25 - 6 - 9 - 24 - 22 - 24)
2
Its negative reciprocal. (-b/a)
4.25 - 6 - 22
Arc length = (n/360) x pi(2r) where n is the number of degrees.

42. (x^2)^4
x^(2(4)) =x^8 = (x^4)^2
No - only like radicals can be added.
An angle which is supplementary to an interior angle.
Cd

43. Area of a triangle?
Pi is the ratio of a circle'S circumference to its diameter.
An expression with just one term (-6x - 2a^2)
1/(x^y)
(base*height) / 2

44. What is the absolute value function?
Yes - like radicals can be added/subtracted.
62.5%
10
G(x) = {x}

45. When the 'a' in a parabola is positive....
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
F(x) - c
6 : 1 : 2
The curve opens upward and the vertex is the minimal point on the graph.

46. What are congruent triangles?
Triangles with same measure and same side lengths.
2(pi)r^2 + 2(pi)rh
Pi is the ratio of a circle'S circumference to its diameter.
83.333%

47. What is the slope of a vertical line?

48. 0^0
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
True
9 & 6/7
Undefined

49. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
90
Even
0

50. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
...multiply by 100.
From northeast - counterclockwise. I - II - III - IV
4:5
4725