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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 name for a grouping of the members within a set based on a shared characteristic?
A subset.
A chord is a line segment joining two points on a circle.
No - only like radicals can be added.
Area of the base X height = (pi)hr^2

2. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
C = (pi)d
5
Arc length = (n/360) x pi(2r) where n is the number of degrees.
4725

3. 10<all primes<20
20.5
11 - 13 - 17 - 19
A tangent is a line that only touches one point on the circumference of a circle.
2 & 3/7

4. When the 'a' in the parabola is negative...
8
No - the input value has exactly one output.
The curve opens downward and the vertex is the maximum point on the graph.
13

5. How many multiples does a given number have?
Infinite.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
A circle centered on the origin with radius 8.
Yes. [i.e. f(x) = x^2 - 1

6. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
3 - -3
70
500
C = (pi)d

7. What is a minor arc?

8. a^2 - 2ab + b^2
$3 -500 in the 9% and $2 -500 in the 7%.
(a - b)^2
A = pi(r^2)
Yes. [i.e. f(x) = x^2 - 1

9. To convert a percent to a fraction....
The set of output values for a function.
Cd
Area of the base X height = (pi)hr^2
Divide by 100.

10. What percent of 40 is 22?
1/(x^y)
31 - 37
2sqrt6
55%

11. (x^2)^4
1.7
x^(2(4)) =x^8 = (x^4)^2
Undefined
The set of input values for a function.

12. sqrt 2(sqrt 6)=
1
A = pi(r^2)
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
Sqrt 12

13. In a regular polygon with n sides - the formula for the sum of interior angles
3 - -3
$11 -448
5 OR -5
(n-2) x 180

14. The number of degrees in the largest angle of a triangle inscribed in a circle - in which the diameter of the circle is one side of the triangle.
Move the decimal point to the right x places
The third side is greater than the difference and less than the sum.
500
90 degrees

15. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
(a - b)(a + b)
4:5
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
10

16. How many sides does a hexagon have?
A set with no members - denoted by a circle with a diagonal through it.
A circle centered on the origin with radius 8.
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
6

17. Reduce: 4.8 : 0.8 : 1.6
Sqrt 12
6 : 1 : 2
6
180 degrees

18. Formula to find a circle'S circumference from its diameter?
Sqrt 12
C = (pi)d
1/a^6
(a - b)(a + b)

19. What is the 'domain' of a function?
(amount of increase/original price) x 100%
A 30-60-90 triangle.
The set of input values for a function.
67 - 71 - 73

20. 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.
A set with no members - denoted by a circle with a diagonal through it.
Arc length = (n/360) x pi(2r) where n is the number of degrees.
x^(6-3) = x^3

21. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
The sum of digits is divisible by 9.
Yes - like radicals can be added/subtracted.
A reflection about the axis.
From northeast - counterclockwise. I - II - III - IV

22. What is the side length of an equilateral triangle with altitude 6?
2.592 kg
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...
Move the decimal point to the right x places
F(x + c)

23. The objects in a set are called two names:
... the square of the ratios of the corresponding sides.
413.03 / 10^4 (move the decimal point 4 places to the left)
Members or elements
2 & 3/7

24. 20<all primes<30
C = 2(pi)r
23 - 29
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
288 (8 9 4)

25. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
Pi is the ratio of a circle'S circumference to its diameter.
52
1
Two equal sides and two equal angles.

26. 8.84 / 5.2
x= (1.2)(.8)lw
Pi is the ratio of a circle'S circumference to its diameter.
1.7
Members or elements

27. (6sqrt3) x (2sqrt5) =
1:1:sqrt2
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
The sum of digits is divisible by 9.
y = (x + 5)/2

28. 413.03 x 10^(-4) =
413.03 / 10^4 (move the decimal point 4 places to the left)
(a + b)^2
...multiply by 100.
(b + c)

29. What are complementary angles?
1/(x^y)
Divide by 100.
From northeast - counterclockwise. I - II - III - IV
Two angles whose sum is 90.

30. What is the name of set with a number of elements which cannot be counted?
Ax^2 + bx + c where a -b and c are constants and a /=0
Its negative reciprocal. (-b/a)
An infinite set.
(p + q)/5

31. What is the area of a regular hexagon with side 6?
x^(4+7) = x^11
52
Arc length = (n/360) x pi(2r) where n is the number of degrees.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

32. Define a 'Term' -
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)
9 & 6/7
.0004809 X 10^11
75:11

33. What does the graph x^2 + y^2 = 64 look like?
A chord is a line segment joining two points on a circle.
A circle centered on the origin with radius 8.
37.5%
No - only like radicals can be added.

34. a^2 - b^2 =
(a - b)(a + b)
(b + c)
A tangent is a line that only touches one point on the circumference of a circle.
The interesection of A and B.

35. What is an isoceles triangle?
No - only like radicals can be added.
12.5%
55%
Two equal sides and two equal angles.

36. Whats the difference between factors and multiples?
Undefined
Angle/360 x (pi)r^2
... the square of the ratios of the corresponding sides.
Factors are few - multiples are many.

37. What is the 'Range' of a series of numbers?
A 30-60-90 triangle.
2.592 kg
The greatest value minus the smallest.
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.

38. A number is divisible by 3 if ...
13pi / 2
Factors are few - multiples are many.
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 sum of its digits is divisible by 3.

39. What is it called when a point is reflected to the quadrant opposite it (i.e. I to III or II to IV)?
A reflection about the origin.
A grouping of the members within a set based on a shared characteristic.
Two angles whose sum is 180.
Lies opposite the greater angle

40. 1:sqrt3:2 is the ratio of the sides of what kind of triangle?
1 & 37/132
Its last two digits are divisible by 4.
A 30-60-90 triangle.
True

41. 200 <_ x <_ 300. How many values of x are divisible by 5 & 8?
3
10! / (10-3)! = 720
41 - 43 - 47
An angle which is supplementary to an interior angle.

42. 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
A set with a number of elements which can be counted.
x(x - y + 1)
$3 -500 in the 9% and $2 -500 in the 7%.

43. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
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.
2^9 / 2 = 256
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

44. (-1)^3 =
1
3
4:5
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.

45. What is the maximum value for the function g(x) = (-2x^2) -1?
3sqrt4
A 30-60-90 triangle.
1
441000 = 1 10 10 10 21 * 21

46. The larger the absolute value of the slope...
x= (1.2)(.8)lw
The steeper the slope.
The sum of its digits is divisible by 3.
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)

47. 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?
Triangles with same measure and same side lengths.
$3 -500 in the 9% and $2 -500 in the 7%.
The greatest value minus the smallest.
180 degrees

48. What is a parabola?
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
1
27^(-4)
Ax^2 + bx + c where a -b and c are constants and a /=0

49. Simplify the expression (p^2 - q^2)/ -5(q - p)
1
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
(p + q)/5
The overlapping sections.

50. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
x= (1.2)(.8)lw
A circle centered at -2 - -2 with radius 3.
28. n = 8 - k = 2. n! / k!(n-k)!
The second graph is less steep.