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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 are the irrational numbers?

2. The perimeter of a square is 48 inches. The length of its diagonal is:
12sqrt2
Angle/360 x 2(pi)r
The point of intersection of the systems.
Undefined

3. A number is divisible by 9 if...
Two angles whose sum is 180.
The sum of digits is divisible by 9.
2 & 3/7
Two angles whose sum is 90.

4. Legs 5 - 12. Hypotenuse?
500
Sqrt 12
1
13

5. What is the slope of a horizontal line?
52
0
A chord is a line segment joining two points on a circle.
37.5%

6. What are the rational numbers?
The set of output values for a function.
31 - 37
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
6

7. Formula of rectangle where l increases by 20% and w decreases by 20%
5 OR -5
(n-2) x 180
The steeper the slope.
x= (1.2)(.8)lw

8. What is a parabola?
11 - 13 - 17 - 19
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
Ax^2 + bx + c where a -b and c are constants and a /=0
23 - 29

9. x^6 / x^3
The set of input values for a function.
12sqrt2
The curve opens downward and the vertex is the maximum point on the graph.
x^(6-3) = x^3

10. What is the area of a regular hexagon with side 6?
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
Infinite.
1 & 37/132
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).

11. What is the 'Solution' for a system of linear equations?
The interesection of A and B.
An infinite set.
Its divisible by 2 and by 3.
The point of intersection of the systems.

12. What are 'Supplementary angles?'
3 - -3
Two angles whose sum is 180.
2 & 3/7
9 & 6/7

13. Evaluate 3& 2/7 / 1/3
9 & 6/7
413.03 / 10^4 (move the decimal point 4 places to the left)
True
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)

14. What is the 'Range' of a function?
Ax^2 + bx + c where a -b and c are constants and a /=0
The set of output values for a function.
Yes. [i.e. f(x) = x^2 - 1
2

15. What is the set of elements found in both A and B?
The shortest arc between points A and B on a circle'S diameter.
13pi / 2
The interesection of A and B.
4725

16. 5/6 in percent?
Move the decimal point to the right x places
(base*height) / 2
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
83.333%

17. 20<all primes<30
1:1:sqrt2
23 - 29
The point of intersection of the systems.
1

18. sqrt 2(sqrt 6)=
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
1:sqrt3:2
Sqrt 12
All numbers multiples of 1.

19. 40 < all primes<50
(a + b)^2
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.
41 - 43 - 47
55%

20. What are the real numbers?
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 longest arc between points A and B on a circle'S diameter.
9 & 6/7
(b + c)

21. What is the graph of f(x) shifted right c units or spaces?
F(x-c)
70
4a^2(b)
41 - 43 - 47

22. What is the absolute value function?
G(x) = {x}
18
An arc is a portion of a circumference of a circle.
500

23. 1/8 in percent?
12.5%
x^(2(4)) =x^8 = (x^4)^2
Two angles whose sum is 90.
A reflection about the axis.

24. What are complementary angles?
71 - 73 - 79
Two angles whose sum is 90.
$3 -500 in the 9% and $2 -500 in the 7%.
2 & 3/7

25. Order of quadrants:
Angle/360 x 2(pi)r
Two equal sides and two equal angles.
From northeast - counterclockwise. I - II - III - IV
(b + c)

26. Pi is a ratio of what to what?

27. What is the side length of an equilateral triangle with altitude 6?
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...
A circle centered at -2 - -2 with radius 3.
5 OR -5
II

28. Which quadrant is the lower left hand?
37.5%
x= (1.2)(.8)lw
III
(a - b)(a + b)

29. A number is divisible by 3 if ...
Relationship cannot be determined (what if x is negative?)
27^(-4)
A reflection about the origin.
The sum of its digits is divisible by 3.

30. What percent of 40 is 22?
70
II
4725
55%

31. How to find the area of a sector?
Angle/360 x (pi)r^2
The sum of its digits is divisible by 3.
500
Move the decimal point to the right x places

32. Factor x^2 - xy + x.
x(x - y + 1)
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
1/a^6
Its last two digits are divisible by 4.

33. How many sides does a hexagon have?
10! / (10-3)! = 720
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
Pi is the ratio of a circle'S circumference to its diameter.
6

34. 5/8 in percent?
62.5%
1
A circle centered on the origin with radius 8.
x(x - y + 1)

35. What is the sum of the angles of a triangle?
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)
From northeast - counterclockwise. I - II - III - IV
180 degrees
3/2 - 5/3

36. The larger the absolute value of the slope...
The steeper the slope.
288 (8 9 4)
The overlapping sections.
4:5

37. What is the 'domain' of a function?
31 - 37
3
x^(2(4)) =x^8 = (x^4)^2
The set of input values for a function.

38. 6w^2 - w - 15 = 0
Two equal sides and two equal angles.
3/2 - 5/3
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
41 - 43 - 47

39. A number is divisible by 4 is...
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
A central angle is an angle formed by 2 radii.
The union of A and B.
Its last two digits are divisible by 4.

40. What is the maximum value for the function g(x) = (-2x^2) -1?
61 - 67
A grouping of the members within a set based on a shared characteristic.
A reflection about the axis.
1

41. Nine coins are tossed simultaneously. In how many of the outcomes will the fourth coin tossed show heads?
1 & 37/132
2^9 / 2 = 256
90
31 - 37

42. What is the percent formula?
Part = Percent X Whole
Two angles whose sum is 180.
12sqrt2
No - only like radicals can be added.

43. What is the order of operations?
18
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
Pi is the ratio of a circle'S circumference to its diameter.
Factors are few - multiples are many.

44. What is the 'Range' of a series of numbers?
27^(-4)
F(x-c)
The greatest value minus the smallest.
13pi / 2

45. How to determine percent increase?
A set with no members - denoted by a circle with a diagonal through it.
(amount of increase/original price) x 100%
1
61 - 67

46. (-1)^2 =
75:11
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)
90 degrees

47. 10^6 has how many zeroes?
6
The curve opens upward and the vertex is the minimal point on the graph.
48
9 : 25

48. Employee X is paid 19.50 per hour no matter how many a week. Employee Y earns 18 for the first 40 and 1.5 the hourly wage for every hour after that. If both earned the same amount and worked the same in one week - how many did each work?
27^(-4)
48
The interesection of A and B.
Angle/360 x (pi)r^2

49. Which quadrant is the upper right hand?
I
A reflection about the axis.
Move the decimal point to the right x places
A grouping of the members within a set based on a shared characteristic.

50. There are 10 finalists for the school spelling bee. A first - second - and third place trophy will be awarded. In how many ways can the judges award the 3 prizes?
7 / 1000
10! / (10-3)! = 720
1/a^6
The set of output values for a function.