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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. How many multiples does a given number have?
...multiply by 100.
I
18
Infinite.

2. 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)
4:5
180
A grouping of the members within a set based on a shared characteristic.

3. Which quadrant is the upper left hand?
The set of output values for a function.
3 - -3
II
72

4. What is the absolute value function?
Arc length = (n/360) x pi(2r) where n is the number of degrees.
IV
G(x) = {x}
61 - 67

5. P and r are factors of 100. What is greater - pr or 100?
(b + c)
Indeterminable.
2 & 3/7
The shortest arc between points A and B on a circle'S diameter.

6. 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?
(b + c)
Members or elements
9 : 25
Two angles whose sum is 90.

7. What is the slope of a horizontal line?
12sqrt2
441000 = 1 10 10 10 21 * 21
Triangles with same measure and same side lengths.
0

8. What is the coefficient of the x^2 term in the product of (x + 1)(x + 2)(x -1)?
Its last two digits are divisible by 4.
2
G(x) = {x}
A central angle is an angle formed by 2 radii.

9. Simplify the expression (p^2 - q^2)/ -5(q - p)
55%
II
(p + q)/5
(a + b)^2

10. a^2 - b^2 =
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
9 : 25
A = pi(r^2)
(a - b)(a + b)

11. In a regular polygon with n sides - the formula for the sum of interior angles
A set with a number of elements which can be counted.
48
(n-2) x 180
8

12. Define an 'expression'.
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 chord is a line segment joining two points on a circle.
The set of input values for a function.
12! / 5!7! = 792

13. 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?
75:11
Infinite.
4:5
7 / 1000

14. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
.0004809 X 10^11
70
1 & 37/132
83.333%

15. a^2 - b^2
Members or elements
2^9 / 2 = 256
An angle which is supplementary to an interior angle.
(a - b)(a + b)

16. What are the smallest three prime numbers greater than 65?
6
When the function is not defined for all real numbers -; only a subset of the real numbers.
67 - 71 - 73
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]

17. What is the set of elements found in both A and B?
An angle which is supplementary to an interior angle.
The interesection of A and B.
x^(6-3) = x^3
11 - 13 - 17 - 19

18. The objects in a set are called two names:
A tangent is a line that only touches one point on the circumference of a circle.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
Members or elements
F(x) - c

19. How to find the area of a sector?
Angle/360 x (pi)r^2
3/2 - 5/3
1:sqrt3:2
An expression with just one term (-6x - 2a^2)

20. Evaluate 4/11 + 11/12
1 & 37/132
The shortest arc between points A and B on a circle'S diameter.
(a + b)^2
Its negative reciprocal. (-b/a)

21. 5/6 in percent?
3/2 - 5/3
2 & 3/7
83.333%
Cd

22. 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)]?
True
9 : 25
5 OR -5
23 - 29

23. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
413.03 / 10^4 (move the decimal point 4 places to the left)
A reflection about the axis.
41 - 43 - 47
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

24. Circumference of a circle?
Part = Percent X Whole
Angle/360 x 2(pi)r
Diameter(Pi)
9 : 25

25. (a^-1)/a^5
...multiply by 100.
A grouping of the members within a set based on a shared characteristic.
1/a^6
1

26. 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?
4725
71 - 73 - 79
48
(p + q)/5

27. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
(b + c)
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
500
Cd

28. The ratio of the areas of two similar polygons is ...
The curve opens downward and the vertex is the maximum point on the graph.
Lies opposite the greater angle
0
... the square of the ratios of the corresponding sides.

29. The larger the absolute value of the slope...
Its last two digits are divisible by 4.
1/a^6
The steeper the slope.
500

30. What is a subset?
The third side is greater than the difference and less than the sum.
(a - b)^2
A grouping of the members within a set based on a shared characteristic.
(a + b)^2

31. Legs: 3 - 4. Hypotenuse?
23 - 29
5
70
N! / (n-k)!

32. Can you simplify sqrt72?
12.5%
Yes - like radicals can be added/subtracted.
Area of the base X height = (pi)hr^2
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.

33. 50 < all primes< 60
Two angles whose sum is 90.
53 - 59
18
II

34. To convert a percent to a fraction....
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)
Divide by 100.
Ax^2 + bx + c where a -b and c are constants and a /=0
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.

35. Area of a triangle?
A tangent is a line that only touches one point on the circumference of a circle.
(base*height) / 2
5 OR -5
Members or elements

36. What is the ratio of the sides of a 30-60-90 triangle?
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
1:sqrt3:2
2sqrt6
0

37. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
The curve opens downward and the vertex is the maximum point on the graph.
90 degrees
3
4725

38. How to find the diagonal of a rectangular solid?
An arc is a portion of a circumference of a circle.
Its last two digits are divisible by 4.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
A set with a number of elements which can be counted.

39. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
90
No - the input value has exactly one output.
75:11
Pi is the ratio of a circle'S circumference to its diameter.

40. 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)
12.5%
An arc is a portion of a circumference of a circle.
4.25 - 6 - 22
1

41. Which is greater? 64^5 or 16^8
18
48
Undefined
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

42. The slope of a line perpendicular to (a/b)?
Pi is the ratio of a circle'S circumference to its diameter.
2sqrt6
Its negative reciprocal. (-b/a)
Arc length = (n/360) x pi(2r) where n is the number of degrees.

43. 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?
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
52
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
4a^2(b)

44. 5/8 in percent?
53 - 59
62.5%
9 & 6/7
413.03 / 10^4 (move the decimal point 4 places to the left)

45. (x^2)^4
2sqrt6
x^(2(4)) =x^8 = (x^4)^2
Undefined - because we can'T divide by 0.
Sector area = (n/360) X (pi)r^2

46. 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?
Yes - like radicals can be added/subtracted.
Yes. [i.e. f(x) = x^2 - 1
(a - b)(a + b)
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

47. x^(-y)=
The second graph is less steep.
(a + b)^2
16.6666%
1/(x^y)

48. What is an exterior angle?
70
31 - 37
3
An angle which is supplementary to an interior angle.

49. 10<all primes<20
x= (1.2)(.8)lw
1
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
11 - 13 - 17 - 19

50. Describe the relationship between 3x^2 and 3(x - 1)^2
(a + b)^2
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
0
A reflection about the axis.