Test your basic knowledge |

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. Factor a^2 + 2ab + b^2
A = pi(r^2)
3 - -3
A central angle is an angle formed by 2 radii.
(a + b)^2

2. 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?
The interesection of A and B.
The set of input values for a function.
48
Diameter(Pi)

3. What percent of 40 is 22?
The point of intersection of the systems.
The set of input values for a function.
55%
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

4. Formula to calculate arc length?
Arc length = (n/360) x pi(2r) where n is the number of degrees.
Diameter(Pi)
A circle centered on the origin with radius 8.
F(x) + c

5. A brick with dimensions 10. 15 and 25 weighs 1.5 kg. A second brick (same density) has dimensions 12 - 18 - and 30. What is the weight of the second brick?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
2.592 kg
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
67 - 71 - 73

6. If a=-1 and b=3 - what is the value of (4(a^3)(b^2) - 12(a^2)(b^5)) / (16(a^3)(b^2))?
20.5
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)
x^(2(4)) =x^8 = (x^4)^2
From northeast - counterclockwise. I - II - III - IV

7. To convert a decimal to a percent...
...multiply by 100.
3/2 - 5/3
0
Relationship cannot be determined (what if x is negative?)

8. What is an exterior angle?
An angle which is supplementary to an interior angle.
$3 -500 in the 9% and $2 -500 in the 7%.
From northeast - counterclockwise. I - II - III - IV
(12/2) x (sqrt15 / sqrt5) = 6sqrt3

9. Solve the quadratic equation ax^2 + bx + c= 0
23 - 29
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
12sqrt2
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a

10. What is the slope of a vertical line?

11. A number is divisible by 9 if...
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
(base*height) / 2
The sum of digits is divisible by 9.
1.0843 X 10^11

12. What is a finite set?
The second graph is less steep.
A reflection about the axis.
4725
A set with a number of elements which can be counted.

13. Nine coins are tossed simultaneously. In how many of the outcomes will the fourth coin tossed show heads?
4a^2(b)
1
F(x-c)
2^9 / 2 = 256

14. Order of quadrants:
1
(n-2) x 180
62.5%
From northeast - counterclockwise. I - II - III - IV

15. Simplify 4sqrt21 X 5sqrt2 / 10sqrt7
2sqrt6
7 / 1000
Triangles with same measure and same side lengths.
The set of output values for a function.

16. What are complementary angles?
Diameter(Pi)
130pi
Two angles whose sum is 90.
6 : 1 : 2

17. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
$11 -448
1
90
0

18. 7/8 in percent?
The shortest arc between points A and B on a circle'S diameter.
x= (1.2)(.8)lw
500
87.5%

19. How many 3-digit positive integers are even and do not contain the digit 4?
90pi
41 - 43 - 47
(amount of decrease/original price) x 100%
288 (8 9 4)

20. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
A grouping of the members within a set based on a shared characteristic.
I
90
6 : 1 : 2

21. Simplify the expression [(b^2 - c^2) / (b - c)]
70
(b + c)
2
The point of intersection of the systems.

22. 25^(1/2) or sqrt. 25 =
1
(a - b)^2
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
5 OR -5

23. Which is greater? 27^(-4) or 9^(-8)
0
27^(-4)
16.6666%
The curve opens upward and the vertex is the minimal point on the graph.

24. 70 < all primes< 80
Yes - like radicals can be added/subtracted.
71 - 73 - 79
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
500

25. What is the area of a regular hexagon with side 6?
1
5
The greatest value minus the smallest.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

26. The perimeter of a square is 48 inches. The length of its diagonal is:
52
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
1 & 37/132
12sqrt2

27. What is an arc of a circle?
From northeast - counterclockwise. I - II - III - IV
An arc is a portion of a circumference of a circle.
F(x-c)
A tangent is a line that only touches one point on the circumference of a circle.

28. Describe the relationship between 3x^2 and 3(x - 1)^2
3
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
10! / (10-3)! = 720
Area of the base X height = (pi)hr^2

29. Evaluate 4/11 + 11/12
The overlapping sections.
1 & 37/132
288 (8 9 4)
Two equal sides and two equal angles.

30. What is a major arc?

31. 60 < all primes <70
The overlapping sections.
4:5
61 - 67
Two angles whose sum is 90.

32. A cylinder has surface area 22pi. If the cylinder has a height of 10 - what is its radius?
(a - b)(a + b)
1
3
The set of output values for a function.

33. What is a subset?
3
16.6666%
6 : 1 : 2
A grouping of the members within a set based on a shared characteristic.

34. For similar triangles - the ratio of their corresponding sides is 2:3. What is the ratio of their areas?
The set of elements found in both A and B.
y = (x + 5)/2
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
11 - 13 - 17 - 19

35. Which is greater? 200x^295 or 10x^294?
Relationship cannot be determined (what if x is negative?)
1
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.
No - the input value has exactly one output.

36. Circumference of a circle?
Diameter(Pi)
180 degrees
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
72

37. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
1
Members or elements
Cd
A reflection about the axis.

38. When the 'a' in the parabola is negative...
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
The curve opens downward and the vertex is the maximum point on the graph.
Relationship cannot be determined (what if x is negative?)

39. 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?
Move the decimal point to the right x places
10! / (10-3)! = 720
Undefined
The sum of its digits is divisible by 3.

40. P and r are factors of 100. What is greater - pr or 100?
Indeterminable.
4.25 - 6 - 22
(amount of decrease/original price) x 100%
5 OR -5

41. What is the graph of f(x) shifted upward c units or spaces?
F(x) + c
Two equal sides and two equal angles.
37.5%
.0004809 X 10^11

42. (a^-1)/a^5
1/a^6
4:5
Area of the base X height = (pi)hr^2
61 - 67

43. 1/8 in percent?
(amount of decrease/original price) x 100%
4a^2(b)
A subset.
12.5%

44. How to find the circumference of a circle which circumscribes a square?
10! / (10-3)! = 720
6
The second graph is less steep.
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

45. The objects in a set are called two names:
Members or elements
A reflection about the axis.
The greatest value minus the smallest.
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)

46. The number of degrees in the largest angle of a triangle inscribed in a circle - in which the diameter of the circle is one side of the triangle.
90 degrees
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
(b + c)
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.

47. 1:sqrt3:2 is the ratio of the sides of what kind of triangle?
4:5
12.5%
The overlapping sections.
A 30-60-90 triangle.

48. (x^2)^4
6
Lies opposite the greater angle
The third side is greater than the difference and less than the sum.
x^(2(4)) =x^8 = (x^4)^2

49. a^2 + 2ab + b^2
Two angles whose sum is 90.
(a + b)^2
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
3

50. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
4:5
(b + c)
The overlapping sections.
x^(6-3) = x^3