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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 is the slope of a horizontal line?
11 - 13 - 17 - 19
62.5%
0
...multiply by 100.

2. Simplify 4sqrt21 X 5sqrt2 / 10sqrt7
Indeterminable.
A set with a number of elements which can be counted.
2sqrt6
71 - 73 - 79

3. Factor a^2 + 2ab + b^2
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
0
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)
(a + b)^2

4. (6sqrt3) x (2sqrt5) =
The curve opens upward and the vertex is the minimal point on the graph.
A = pi(r^2)
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
1/a^6

5. Evaluate 4/11 + 11/12
(a - b)(a + b)
Pi is the ratio of a circle'S circumference to its diameter.
Angle/360 x (pi)r^2
1 & 37/132

6. What is the graph of f(x) shifted right c units or spaces?
Relationship cannot be determined (what if x is negative?)
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
F(x-c)
67 - 71 - 73

7. Legs 5 - 12. Hypotenuse?
52
F(x-c)
13
0

8. What are the integers?
The curve opens upward and the vertex is the minimal point on the graph.
Undefined
All numbers multiples of 1.
70

9. Which is greater? 200x^295 or 10x^294?
The sum of digits is divisible by 9.
Yes. [i.e. f(x) = x^2 - 1
61 - 67
Relationship cannot be determined (what if x is negative?)

10. How many sides does a hexagon have?
4:5
6
A 30-60-90 triangle.
Indeterminable.

11. Evaluate 3& 2/7 / 1/3
The curve opens downward and the vertex is the maximum point on the graph.
Yes. [i.e. f(x) = x^2 - 1
37.5%
9 & 6/7

12. Convert 0.7% to a fraction.
7 / 1000
Indeterminable.
Sqrt 12
The sum of digits is divisible by 9.

13. What are the smallest three prime numbers greater than 65?
67 - 71 - 73
N! / (k!)(n-k)!
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
x= (1.2)(.8)lw

14. Simplify the expression (p^2 - q^2)/ -5(q - p)
The set of input values for a function.
N! / (n-k)!
(p + q)/5
The empty set - denoted by a circle with a diagonal through it.

15. A number is divisible by 4 is...
$3 -500 in the 9% and $2 -500 in the 7%.
II
Its last two digits are divisible by 4.
8

16. The larger the absolute value of the slope...
An expression with just one term (-6x - 2a^2)
I
28. n = 8 - k = 2. n! / k!(n-k)!
The steeper the slope.

17. Find the surface area of a cylinder with radius 3 and height 12.
90pi
1:sqrt3:2
Yes. [i.e. f(x) = x^2 - 1
The sum of digits is divisible by 9.

18. 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...
The set of elements which can be found in either A or B.
(a + b)^2
Lies opposite the greater angle

19. 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)
I
x^(2(4)) =x^8 = (x^4)^2
48

20. 6w^2 - w - 15 = 0
53 - 59
70
1
3/2 - 5/3

21. Formula of rectangle where l increases by 20% and w decreases by 20%
The point of intersection of the systems.
x= (1.2)(.8)lw
The union of A and B.
2 & 3/7

22. Which quadrant is the upper left hand?
A = I (1 + rt)
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
Arc length = (n/360) x pi(2r) where n is the number of degrees.
II

23. From a box of 12 candles - you are to remove 5. How many different sets of 5 candles could you remove?
(a + b)^2
The steeper the slope.
12! / 5!7! = 792
A 30-60-90 triangle.

24. Which quadrant is the lower left hand?
III
Move the decimal point to the right x places
1/a^6
Arc length = (n/360) x pi(2r) where n is the number of degrees.

25. 413.03 x 10^(-4) =
20.5
413.03 / 10^4 (move the decimal point 4 places to the left)
67 - 71 - 73
1.7

26. What are 'Supplementary angles?'
Yes. [i.e. f(x) = x^2 - 1
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
Two angles whose sum is 180.
(a + b)^2

27. What is the graph of f(x) shifted downward c units or spaces?
$11 -448
F(x) - c
53 - 59
x^(4+7) = x^11

28. Area of a triangle?
The interesection of A and B.
87.5%
Even
(base*height) / 2

29. What is the set of elements found in both A and B?
A grouping of the members within a set based on a shared characteristic.
I
The interesection of A and B.
288 (8 9 4)

30. 1/6 in percent?
16.6666%
37.5%
1
6

31. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
70
The direction of the inequality is reversed.
52
No - the input value has exactly one output.

32. Formula for the area of a sector of a circle?
An angle which is supplementary to an interior angle.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
Part = Percent X Whole
Sector area = (n/360) X (pi)r^2

33. Length of an arc of a circle?
Angle/360 x (pi)r^2
Angle/360 x 2(pi)r
Pi is the ratio of a circle'S circumference to its diameter.
31 - 37

34. When does a function automatically have a restricted domain (2)?
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
N! / (k!)(n-k)!
3
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.

35. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
(p + q)/5
Arc length = (n/360) x pi(2r) where n is the number of degrees.
90
y = 2x^2 - 3

36. a^2 + 2ab + b^2
(a + b)^2
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
75:11
11 - 13 - 17 - 19

37. Define a 'Term' -
Part = Percent X Whole
130pi
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)
1/a^6

38. 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?
1
75:11
10
3

39. 3/8 in percent?
37.5%
1:sqrt3:2
A set with no members - denoted by a circle with a diagonal through it.
1/2 times 7/3

40. Describe the relationship between the graphs of x^2 and (1/2)x^2
The steeper the slope.
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)
3sqrt4
The second graph is less steep.

41. What is the ratio of the sides of an isosceles right triangle?
1:1:sqrt2
Ax^2 + bx + c where a -b and c are constants and a /=0
Sqrt 12
3

42. What is the measure of an exterior angle of a regular pentagon?
The direction of the inequality is reversed.
413.03 / 10^4 (move the decimal point 4 places to the left)
72
The empty set - denoted by a circle with a diagonal through it.

43. What is the 'domain' of a function?
The set of input values for a function.
From northeast - counterclockwise. I - II - III - IV
180 degrees
90pi

44. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
3/2 - 5/3
...multiply by 100.
2 & 3/7
Cd

45. 40 < all primes<50
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)
41 - 43 - 47
Its last two digits are divisible by 4.
8

46. If an inequality is multiplied or divided by a negative number....
10
The direction of the inequality is reversed.
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)
1

47. a^0 =
1
2^9 / 2 = 256
20.5
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)

48. 25^(1/2) or sqrt. 25 =
An arc is a portion of a circumference of a circle.
5 OR -5
53 - 59
2 & 3/7

49. Can the output value of a function have more than one input value?
Yes. [i.e. f(x) = x^2 - 1
Sector area = (n/360) X (pi)r^2
.0004809 X 10^11
4725

50. What are the roots of the quadrinomial x^2 + 2x + 1?
The two xes after factoring.
0
G(x) = {x}
4096