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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. Reduce: 4.8 : 0.8 : 1.6
130pi
The longest arc between points A and B on a circle'S diameter.
12! / 5!7! = 792
6 : 1 : 2

2. What is a parabola?
8
A chord is a line segment joining two points on a circle.
A circle centered on the origin with radius 8.
Ax^2 + bx + c where a -b and c are constants and a /=0

3. (6sqrt3) x (2sqrt5) =
Diameter(Pi)
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
20.5
1/2 times 7/3

4. When does a function automatically have a restricted domain (2)?
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
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
(base*height) / 2
True

5. What is an isoceles triangle?
x= (1.2)(.8)lw
Two equal sides and two equal angles.
10! / (10-3)! = 720
1

6. P and r are factors of 100. What is greater - pr or 100?
Indeterminable.
Even
IV
67 - 71 - 73

7. (a^-1)/a^5
(n-2) x 180
The set of output values for a function.
A reflection about the axis.
1/a^6

8. 5/8 in percent?
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
180 degrees
62.5%
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.

9. x^6 / x^3
(n-2) x 180
x^(6-3) = x^3
N! / (n-k)!
The direction of the inequality is reversed.

10. 6w^2 - w - 15 = 0
A reflection about the axis.
3/2 - 5/3
2
12.5%

11. What does the graph x^2 + y^2 = 64 look like?
Cd
A = I (1 + rt)
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
A circle centered on the origin with radius 8.

12. What is the maximum value for the function g(x) = (-2x^2) -1?
1
1/(x^y)
4a^2(b)
5

13. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
The overlapping sections.
The interesection of A and B.
6
2 & 3/7

14. What is the intersection of A and B?
1/2 times 7/3
The union of A and B.
The set of elements found in both A and B.
$11 -448

15. 60 < all primes <70
1/(x^y)
61 - 67
N! / (k!)(n-k)!
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.

16. 20<all primes<30
Undefined
F(x-c)
23 - 29
5

17. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
1.7
An angle which is supplementary to an interior angle.
Pi is the ratio of a circle'S circumference to its diameter.
4:5

18. Write 10 -843 X 10^7 in scientific notation
1/a^6
Infinite.
288 (8 9 4)
1.0843 X 10^11

19. What is the graph of f(x) shifted downward c units or spaces?
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
(p + q)/5
A reflection about the axis.
F(x) - c

20. Formula for the area of a circle?
F(x) + c
A = pi(r^2)
1/(x^y)
From northeast - counterclockwise. I - II - III - IV

21. What is the name of set with a number of elements which cannot be counted?
0
3sqrt4
1
An infinite set.

22. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
The interesection of A and B.
x= (1.2)(.8)lw
90 degrees
Cd

23. How to find the area of a sector?
The union of A and B.
Angle/360 x (pi)r^2
C = (pi)d
The third side is greater than the difference and less than the sum.

24. x^(-y)=
1/(x^y)
Yes. [i.e. f(x) = x^2 - 1
The steeper the slope.
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.

25. 25^(1/2) or sqrt. 25 =
3/2 - 5/3
Its divisible by 2 and by 3.
5 OR -5
130pi

26. 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))?
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
True
20.5
Yes. [i.e. f(x) = x^2 - 1

27. Surface area for a cylinder?
G(x) = {x}
2(pi)r^2 + 2(pi)rh
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.

28. Evaluate 4/11 + 11/12
10
48
1 & 37/132
The second graph is less steep.

29. A number is divisible by 4 is...
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
Its last two digits are divisible by 4.
N! / (n-k)!
x^(4+7) = x^11

30. What is an arc of a circle?
Divide by 100.
27^(-4)
5 OR -5
An arc is a portion of a circumference of a circle.

31. Hector invested $6000. Part was invested in account with 9% simple annual interest - and the rest in account with 7% simple annual interest. If he earned $490 in the first year of these investments - how much did he invest in each account?
71 - 73 - 79
$3 -500 in the 9% and $2 -500 in the 7%.
An infinite set.
From northeast - counterclockwise. I - II - III - IV

32. 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?
A grouping of the members within a set based on a shared characteristic.
31 - 37
The curve opens downward and the vertex is the maximum point on the graph.
48

33. 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?
Part = Percent X Whole
10! / 3!(10-3)! = 120
A chord is a line segment joining two points on a circle.
52

34. 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
I
From northeast - counterclockwise. I - II - III - IV
Two angles whose sum is 90.

35. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
(a + b)^2
The two xes after factoring.
1
When the function is not defined for all real numbers -; only a subset of the real numbers.

36. Factor a^2 + 2ab + b^2
(p + q)/5
4.25 - 6 - 22
180 degrees
(a + b)^2

37. Can the input value of a function have more than one output value (i.e. x: y - y1)?
A circle centered at -2 - -2 with radius 3.
The union of A and B.
No - the input value has exactly one output.
13

38. Which quadrant is the upper left hand?
Triangles with same measure and same side lengths.
II
G(x) = {x}
3/2 - 5/3

39. 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?
Cd
...multiply by 100.
9 : 25
9 & 6/7

40. What are the integers?
Lies opposite the greater angle
1.7
4.25 - 6 - 22
All numbers multiples of 1.

41. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
A set with a number of elements which can be counted.
4725
2.592 kg
4a^2(b)

42. Describe the relationship between 3x^2 and 3(x - 1)^2
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
6 : 1 : 2
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
13

43. Define a 'Term' -
The curve opens upward and the vertex is the minimal point on the graph.
(a - b)(a + b)
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
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)

44. Formula to find a circle'S circumference from its diameter?
C = (pi)d
10! / 3!(10-3)! = 120
Divide by 100.
2sqrt6

45. What is the graph of f(x) shifted right c units or spaces?
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
1 & 37/132
F(x-c)
A subset.

46. How many sides does a hexagon have?
The union of A and B.
Undefined - because we can'T divide by 0.
6
y = 2x^2 - 3

47. Legs 5 - 12. Hypotenuse?
11 - 13 - 17 - 19
13
90
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.

48. 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?
F(x) + c
The sum of its digits is divisible by 3.
48
2.592 kg

49. To multiply a number by 10^x
2sqrt6
Move the decimal point to the right x places
A = I (1 + rt)
A subset.

50. What is the empty set?
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)
12.5%
A set with no members - denoted by a circle with a diagonal through it.
2.592 kg