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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. Which is greater? 200x^295 or 10x^294?
C = (pi)d
Relationship cannot be determined (what if x is negative?)
2
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)

2. Formula to find a circle'S circumference from its diameter?
x^(6-3) = x^3
Yes. [i.e. f(x) = x^2 - 1
The set of elements found in both A and B.
C = (pi)d

3. Evaluate 4/11 + 11/12
1/(x^y)
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 & 37/132
18

4. Max and Min lengths for a side of a triangle?
F(x + c)
52
1 & 37/132
The third side is greater than the difference and less than the sum.

5. To convert a percent to a fraction....
Relationship cannot be determined (what if x is negative?)
Divide by 100.
The set of output values for a function.
(a + b)^2

6. How to determine percent increase?
90pi
12! / 5!7! = 792
(amount of increase/original price) x 100%
A 30-60-90 triangle.

7. What number between 70 & 75 - inclusive - has the greatest number of factors?
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
A reflection about the axis.
C = 2(pi)r
72

8. What are congruent triangles?
Triangles with same measure and same side lengths.
62.5%
The direction of the inequality is reversed.
Indeterminable.

9. A number is divisible by 9 if...
x= (1.2)(.8)lw
The sum of digits is divisible by 9.
4096
A reflection about the axis.

10. Legs 6 - 8. Hypotenuse?
10
x^(2(4)) =x^8 = (x^4)^2
A set with no members - denoted by a circle with a diagonal through it.
.0004809 X 10^11

11. Simplify the expression [(b^2 - c^2) / (b - c)]
Lies opposite the greater angle
(b + c)
1
Infinite.

12. What is the 'Restricted domain of a function'?
When the function is not defined for all real numbers -; only a subset of the real numbers.
Angle/360 x (pi)r^2
The empty set - denoted by a circle with a diagonal through it.
The direction of the inequality is reversed.

13. How many multiples does a given number have?
Infinite.
F(x-c)
Undefined - because we can'T divide by 0.
10! / 3!(10-3)! = 120

14. What is a parabola?
The set of input values for a function.
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
Ax^2 + bx + c where a -b and c are constants and a /=0
A reflection about the axis.

15. What is the 'Solution' for a system of linear equations?
The point of intersection of the systems.
An angle which is supplementary to an interior angle.
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

16. Which quadrant is the upper left hand?
II
An arc is a portion of a circumference of a circle.
(a - b)(a + b)
31 - 37

17. How to find the circumference of a circle which circumscribes a square?
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
Undefined
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
1/2 times 7/3

18. 5/6 in percent?
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
441000 = 1 10 10 10 21 * 21
83.333%
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. What is the graph of f(x) shifted right c units or spaces?
F(x-c)
53 - 59
71 - 73 - 79
The sum of its digits is divisible by 3.

20. Can the output value of a function have more than one input value?
Its last two digits are divisible by 4.
The point of intersection of the systems.
$11 -448
Yes. [i.e. f(x) = x^2 - 1

21. What is a tangent?
12sqrt2
55%
A tangent is a line that only touches one point on the circumference of a circle.
The empty set - denoted by a circle with a diagonal through it.

22. What is a major arc?

23. 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...
2^9 / 2 = 256
When the function is not defined for all real numbers -; only a subset of the real numbers.
A set with a number of elements which can be counted.

24. The objects in a set are called two names:
Factors are few - multiples are many.
The empty set - denoted by a circle with a diagonal through it.
Indeterminable.
Members or elements

25. Is 0 even or odd?
1.0843 X 10^11
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...
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
Even

26. What is the formula for computing simple interest?
(amount of decrease/original price) x 100%
12.5%
A = I (1 + rt)
The steeper the slope.

27. What are the integers?
500
IV
All numbers multiples of 1.
3

28. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
90 degrees
3/2 - 5/3
A subset.
4725

29. 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?
90
y = 2x^2 - 3
Undefined - because we can'T divide by 0.
The second graph is less steep.

30. What is the ratio of the sides of an isosceles right triangle?
The set of elements which can be found in either A or B.
2(pi)r^2 + 2(pi)rh
1:1:sqrt2
Its negative reciprocal. (-b/a)

31. What is the slope of a horizontal line?
10! / 3!(10-3)! = 120
Yes - like radicals can be added/subtracted.
No - the input value has exactly one output.
0

32. There are 10 finalists for the school spelling bee. A first - second - and third place trophy will be awarded. In how many ways can the judges award the 3 prizes?
10! / (10-3)! = 720
Its divisible by 2 and by 3.
6
The set of input values for a function.

33. What is the name for a grouping of the members within a set based on a shared characteristic?
(b + c)
.0004809 X 10^11
A subset.
13pi / 2

34. What is the 'Solution' for a set of inequalities.
The sum of digits is divisible by 9.
The overlapping sections.
y = 2x^2 - 3
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

35. What does scientific notation mean?
180 degrees
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
(a + b)^2
441000 = 1 10 10 10 21 * 21

36. a^2 + 2ab + b^2
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
4725
The union of A and B.
(a + b)^2

37. (x^2)^4
N! / (n-k)!
(a + b)^2
1/(x^y)
x^(2(4)) =x^8 = (x^4)^2

38. How many sides does a hexagon have?
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
x^(6-3) = x^3
6
2.592 kg

39. The perimeter of a square is 48 inches. The length of its diagonal is:
12sqrt2
72
48
The set of output values for a function.

40. 3/8 in percent?
1 & 37/132
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
67 - 71 - 73
37.5%

41. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
Ax^2 + bx + c where a -b and c are constants and a /=0
The set of elements which can be found in either A or B.
2sqrt6
A reflection about the axis.

42. 2sqrt4 + sqrt4 =
87.5%
A tangent is a line that only touches one point on the circumference of a circle.
3sqrt4
x^(4+7) = x^11

43. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
70
Angle/360 x (pi)r^2
Two angles whose sum is 180.
12! / 5!7! = 792

44. What is a chord of a circle?
A chord is a line segment joining two points on a circle.
6 : 1 : 2
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
130pi

45. Can you subtract 3sqrt4 from sqrt4?
Yes. [i.e. f(x) = x^2 - 1
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
Yes - like radicals can be added/subtracted.

46. What is the empty set?
A set with no members - denoted by a circle with a diagonal through it.
1.7
Undefined - because we can'T divide by 0.
A reflection about the axis.

47. What is the 'domain' of a function?
The set of input values for a function.
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
Triangles with same measure and same side lengths.
72

48. Legs: 3 - 4. Hypotenuse?
6
5
Sqrt 12
1/a^6

49. What is the measure of an exterior angle of a regular pentagon?
No - only like radicals can be added.
72
The union of A and B.
A central angle is an angle formed by 2 radii.

50. What is a subset?
2^9 / 2 = 256
A circle centered at -2 - -2 with radius 3.
IV
A grouping of the members within a set based on a shared characteristic.