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. How many sides does a hexagon have?
An arc is a portion of a circumference of a circle.
6
4725
48

2. 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)]?
(amount of increase/original price) x 100%
Undefined - because we can'T divide by 0.
True
x^(4+7) = x^11

3. 200 <_ x <_ 300. How many values of x are divisible by 5 & 8?
3
1
4a^2(b)
(12/2) x (sqrt15 / sqrt5) = 6sqrt3

4. Which quadrant is the upper left hand?
The set of elements found in both A and B.
II
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
Relationship cannot be determined (what if x is negative?)

5. 30< all primes<40
The two xes after factoring.
31 - 37
(a - b)(a + b)
87.5%

6. What is the coefficient of the x^2 term in the product of (x + 1)(x + 2)(x -1)?
An expression with just one term (-6x - 2a^2)
2
C = 2(pi)r
The two xes after factoring.

7. Legs 5 - 12. Hypotenuse?
13
180
2sqrt6
Indeterminable.

8. Is 0 even or odd?
F(x-c)
70
Even
An infinite set.

9. What are the roots of the quadrinomial x^2 + 2x + 1?
Triangles with same measure and same side lengths.
The two xes after factoring.
An infinite set.
37.5%

10. What are the real numbers?
27^(-4)
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)
Yes - like radicals can be added/subtracted.
4.25 - 6 - 22

11. Order of quadrants:
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
From northeast - counterclockwise. I - II - III - IV
1/a^6
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)

12. 20<all primes<30
23 - 29
55%
4:5
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

13. What is the measure of an exterior angle of a regular pentagon?
12! / 5!7! = 792
72
Divide by 100.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

14. 2sqrt4 + sqrt4 =
4a^2(b)
Two angles whose sum is 90.
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
3sqrt4

15. What is the intersection of A and B?
90pi
The set of elements found in both A and B.
The shortest arc between points A and B on a circle'S diameter.
Diameter(Pi)

16. What are the members or elements of a set?
The objects within a set.
The direction of the inequality is reversed.
x^(6-3) = x^3
.0004809 X 10^11

17. Which quadrant is the upper right hand?
F(x) - c
1/a^6
I
1:1:sqrt2

18. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
4725
90pi
1
75:11

19. How many 3-digit positive integers are even and do not contain the digit 4?
288 (8 9 4)
IV
I
.0004809 X 10^11

20. Define a 'Term' -
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
C = (pi)d
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)
41 - 43 - 47

21. What is the order of operations?
Triangles with same measure and same side lengths.
4725
N! / (k!)(n-k)!
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)

22. If you have a set of n objects - but you only want to order k of them - what formula do you use to determine the number of permutations?
1/2 times 7/3
N! / (n-k)!
A central angle is an angle formed by 2 radii.
The curve opens upward and the vertex is the minimal point on the graph.

23. What is a piecewise equation?
1
71 - 73 - 79
The two xes after factoring.
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.

24. The perimeter of a square is 48 inches. The length of its diagonal is:
A set with no members - denoted by a circle with a diagonal through it.
1
12sqrt2
.0004809 X 10^11

25. A triangle is inscribed in a semi circle with legs 5 and 12. What is the circumfermence of the semicircle?
13pi / 2
55%
61 - 67
y = 2x^2 - 3

26. Circumference of a circle?
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
A tangent is a line that only touches one point on the circumference of a circle.
A grouping of the members within a set based on a shared characteristic.
Diameter(Pi)

27. Formula to calculate arc length?
Arc length = (n/360) x pi(2r) where n is the number of degrees.
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)
A central angle is an angle formed by 2 radii.
13pi / 2

28. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
2 & 3/7
2
The set of elements found in both A and B.
y = 2x^2 - 3

29. A number is divisible by 6 if...
An isosceles right triangle.
Its divisible by 2 and by 3.
A circle centered on the origin with radius 8.
From northeast - counterclockwise. I - II - III - IV

30. 413.03 x 10^(-4) =
10! / (10-3)! = 720
413.03 / 10^4 (move the decimal point 4 places to the left)
F(x) + c
The empty set - denoted by a circle with a diagonal through it.

31. To convert a decimal to a percent...
62.5%
8
...multiply by 100.
The set of input values for a function.

32. 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?
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
G(x) = {x}
3 - -3
130pi

33. 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?
A reflection about the axis.
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
1:1:sqrt2

34. Which is greater? 27^(-4) or 9^(-8)
6
1
27^(-4)
1:sqrt3:2

35. 0^0
31 - 37
4a^2(b)
Undefined
3sqrt4

36. What is the area of a regular hexagon with side 6?
48
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
The curve opens downward and the vertex is the maximum point on the graph.
1:1:sqrt2

37. What number between 70 & 75 - inclusive - has the greatest number of factors?
Sector area = (n/360) X (pi)r^2
The point of intersection of the systems.
90 degrees
72

38. 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?
83.333%
13
48
1

39. 6w^2 - w - 15 = 0
0
2
3/2 - 5/3
Indeterminable.

40. (a^-1)/a^5
III
1/2 times 7/3
1/a^6
55%

41. What is an isoceles triangle?
The direction of the inequality is reversed.
(a + b)^2
Two equal sides and two equal angles.
4.25 - 6 - 22

42. Volume for a cylinder?
1
The interesection of A and B.
10! / (10-3)! = 720
Area of the base X height = (pi)hr^2

43. Evaluate 4/11 + 11/12
From northeast - counterclockwise. I - II - III - IV
3
1 & 37/132
A 30-60-90 triangle.

44. a^0 =
3
1
A subset.
83.333%

45. What are 'Supplementary angles?'
When the function is not defined for all real numbers -; only a subset of the real numbers.
11 - 13 - 17 - 19
Two angles whose sum is 180.
The steeper the slope.

46. Which is greater? 64^5 or 16^8
10! / (10-3)! = 720
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
Even
Infinite.

47. 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
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
13
Diameter(Pi)

48. 1/8 in percent?
The objects within a set.
12.5%
A = pi(r^2)
Triangles with same measure and same side lengths.

49. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
A reflection about the axis.
1/2 times 7/3
A = I (1 + rt)
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.

50. Formula for the area of a sector of a circle?
Sector area = (n/360) X (pi)r^2
20.5
1/(x^y)
413.03 / 10^4 (move the decimal point 4 places to the left)