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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 an arc of a circle?
A subset.
An arc is a portion of a circumference of a circle.
Angle/360 x 2(pi)r
Arc length = (n/360) x pi(2r) where n is the number of degrees.

2. What is the 'Solution' for a system of linear equations?
A grouping of the members within a set based on a shared characteristic.
The point of intersection of the systems.
Part = Percent X Whole
3/2 - 5/3

3. x^(-y)=
72
(a + b)^2
5
1/(x^y)

4. Simplify 9^(1/2) X 4^3 X 2^(-6)?
3
The longest arc between points A and B on a circle'S diameter.
All numbers multiples of 1.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

5. For similar triangles - the ratio of their corresponding sides is 2:3. What is the ratio of their areas?
3
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
Indeterminable.
The shortest arc between points A and B on a circle'S diameter.

6. How to determine percent increase?
2.592 kg
Infinite.
An angle which is supplementary to an interior angle.
(amount of increase/original price) x 100%

7. What is the absolute value function?
y = 2x^2 - 3
(a - b)(a + b)
G(x) = {x}
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

8. 0^0
Undefined
72
180
$11 -448

9. Describe the relationship between 3x^2 and 3(x - 1)^2
(b + c)
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
31 - 37
28. n = 8 - k = 2. n! / k!(n-k)!

10. Formula to calculate arc length?
y = (x + 5)/2
(amount of decrease/original price) x 100%
Arc length = (n/360) x pi(2r) where n is the number of degrees.
The set of input values for a function.

11. 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?
$3 -500 in the 9% and $2 -500 in the 7%.
The longest arc between points A and B on a circle'S diameter.
1
Yes - like radicals can be added/subtracted.

12. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
Indeterminable.
Even
1:1:sqrt2
4725

13. The objects in a set are called two names:
Members or elements
Undefined - because we can'T divide by 0.
Angle/360 x 2(pi)r
A reflection about the axis.

14. Simplify 4sqrt21 X 5sqrt2 / 10sqrt7
A chord is a line segment joining two points on a circle.
2sqrt6
An expression with just one term (-6x - 2a^2)
The curve opens upward and the vertex is the minimal point on the graph.

15. Formula to find a circle'S circumference from its radius?
F(x + c)
71 - 73 - 79
C = 2(pi)r
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.

16. What is a parabola?
413.03 / 10^4 (move the decimal point 4 places to the left)
An infinite set.
13
Ax^2 + bx + c where a -b and c are constants and a /=0

17. 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?
N! / (n-k)!
(amount of increase/original price) x 100%
12! / 5!7! = 792
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)

18. What is the formula for compounded interest?
12sqrt2
Its negative reciprocal. (-b/a)
G(x) = {x}
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.

19. a^2 - b^2 =
II
(p + q)/5
(a - b)(a + b)
10! / 3!(10-3)! = 120

20. Can the input value of a function have more than one output value (i.e. x: y - y1)?
... the square of the ratios of the corresponding sides.
No - the input value has exactly one output.
(base*height) / 2
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)

21. Define a 'monomial'
12.5%
18
The sum of its digits is divisible by 3.
An expression with just one term (-6x - 2a^2)

22. To convert a decimal to a percent...
...multiply by 100.
441000 = 1 10 10 10 21 * 21
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
4096

23. What is a central angle?
Part = Percent X Whole
Arc length = (n/360) x pi(2r) where n is the number of degrees.
A central angle is an angle formed by 2 radii.
4:5

24. Write 10 -843 X 10^7 in scientific notation
An angle which is supplementary to an interior angle.
1.0843 X 10^11
Its last two digits are divisible by 4.
3 - -3

25. The perimeter of a square is 48 inches. The length of its diagonal is:
Lies opposite the greater angle
52
12sqrt2
4725

26. What is the intersection of A and B?
(a + b)^2
28. n = 8 - k = 2. n! / k!(n-k)!
The set of elements found in both A and B.
83.333%

27. Order of quadrants:
1
An arc is a portion of a circumference of a circle.
6 : 1 : 2
From northeast - counterclockwise. I - II - III - IV

28. What is the 'Solution' for a set of inequalities.
The overlapping sections.
Undefined
The set of elements which can be found in either A or B.
1

29. How to find the diagonal of a rectangular solid?
3/2 - 5/3
2.592 kg
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).

30. How many multiples does a given number have?
No - the input value has exactly one output.
28. n = 8 - k = 2. n! / k!(n-k)!
Infinite.
180 degrees

31. 50 < all primes< 60
Relationship cannot be determined (what if x is negative?)
Lies opposite the greater angle
The overlapping sections.
53 - 59

32. 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.
Move the decimal point to the right x places
(a + b)^2
(amount of decrease/original price) x 100%

33. 6w^2 - w - 15 = 0
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)
3/2 - 5/3
4a^2(b)
31 - 37

34. Define an 'expression'.
Angle/360 x (pi)r^2
Lies opposite the greater angle
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)
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)

35. A number is divisible by 9 if...
$3 -500 in the 9% and $2 -500 in the 7%.
The sum of digits is divisible by 9.
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.
6

36. What is the graph of f(x) shifted right c units or spaces?
90
Area of the base X height = (pi)hr^2
6 : 1 : 2
F(x-c)

37. 10<all primes<20
The sum of its digits is divisible by 3.
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
2 & 3/7
11 - 13 - 17 - 19

38. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
The sum of digits is divisible by 9.
2
90
G(x) = {x}

39. a^2 + 2ab + b^2
x= (1.2)(.8)lw
The two xes after factoring.
2
(a + b)^2

40. Formula of rectangle where l increases by 20% and w decreases by 20%
x= (1.2)(.8)lw
1:1:sqrt2
Sector area = (n/360) X (pi)r^2
An expression with just one term (-6x - 2a^2)

41. 30< all primes<40
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)
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
31 - 37
1.0843 X 10^11

42. 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)
The second graph is less steep.
Sector area = (n/360) X (pi)r^2
A central angle is an angle formed by 2 radii.

43. 1/2 divided by 3/7 is the same as
61 - 67
1/2 times 7/3
The two xes after factoring.
3 - -3

44. What is a chord of a circle?
A chord is a line segment joining two points on a circle.
10! / 3!(10-3)! = 120
2
3

45. Define a 'Term' -
6 : 1 : 2
10! / (10-3)! = 720
From northeast - counterclockwise. I - II - III - IV
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. 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?
(amount of increase/original price) x 100%
1 & 37/132
52
4:5

47. 1/6 in percent?
441000 = 1 10 10 10 21 * 21
5 OR -5
16.6666%
Arc length = (n/360) x pi(2r) where n is the number of degrees.

48. What are the integers?
The greatest value minus the smallest.
All numbers multiples of 1.
N! / (n-k)!
3

49. Which quadrant is the upper left hand?
II
9 & 6/7
From northeast - counterclockwise. I - II - III - IV
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.

50. 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?
The sum of digits is divisible by 9.
y = 2x^2 - 3
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
500