Test your basic knowledge |

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. Formula for the area of a sector of a circle?
2sqrt6
0
Sector area = (n/360) X (pi)r^2
An arc is a portion of a circumference of a circle.

2. x^2 = 9. What is the value of x?
4.25 - 6 - 22
6
3 - -3
Relationship cannot be determined (what if x is negative?)

3. 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 interesection of A and B.
y = 2x^2 - 3
2sqrt6
...multiply by 100.

4. There are 10 finalists for the school spelling bee. A first - second - and third place trophy will be awarded. How many different people can get the three prizes?
10! / 3!(10-3)! = 120
A reflection about the origin.
An angle which is supplementary to an interior angle.
The set of elements found in both A and B.

5. How to find the diagonal of a rectangular solid?
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
y = 2x^2 - 3
18
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).

6. What is a central angle?
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
C = 2(pi)r
A central angle is an angle formed by 2 radii.
4725

7. What is the intersection of A and B?
The set of elements found in both A and B.
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
8
37.5%

8. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
4725
53 - 59
No - only like radicals can be added.
1:sqrt3:2

9. How many sides does a hexagon have?
Cd
37.5%
Indeterminable.
6

10. To multiply a number by 10^x
1
Move the decimal point to the right x places
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.
An isosceles right triangle.

11. x^4 + x^7 =
71 - 73 - 79
x^(4+7) = x^11
The third side is greater than the difference and less than the sum.
Pi is the ratio of a circle'S circumference to its diameter.

12. From a box of 12 candles - you are to remove 5. How many different sets of 5 candles could you remove?
Two angles whose sum is 180.
6
12! / 5!7! = 792
No - the input value has exactly one output.

13. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
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
The sum of its digits is divisible by 3.

14. Number of degrees in a triangle
180
Lies opposite the greater angle
71 - 73 - 79
1

15. Formula to find a circle'S circumference from its radius?
Part = Percent X Whole
11 - 13 - 17 - 19
C = 2(pi)r
x^(6-3) = x^3

16. Evaluate 3& 2/7 / 1/3
9 & 6/7
4.25 - 6 - 22
130pi
71 - 73 - 79

17. (-1)^3 =
1
72
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
G(x) = {x}

18. What are congruent triangles?
0
Triangles with same measure and same side lengths.
18
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

19. Which quandrant is the lower right hand?
500
Triangles with same measure and same side lengths.
IV
1

20. If the two sides of a triangle are unequal then the longer side...
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.
Lies opposite the greater angle
A = pi(r^2)
10! / 3!(10-3)! = 120

21. Suppose you have a set of n objects - and you want to select k of them - but the order doesn'T matter. What formula do you use to determine the number of combinations of n objects taken k at a time?
10! / (10-3)! = 720
10! / 3!(10-3)! = 120
90
N! / (k!)(n-k)!

22. 30< all primes<40
1:sqrt3:2
31 - 37
G(x) = {x}
1

23. What is the surface area of a cylinder with radius 5 and height 8?
(a - b)(a + b)
The set of output values for a function.
130pi
An angle which is supplementary to an interior angle.

24. 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?
(a - b)(a + b)
A grouping of the members within a set based on a shared characteristic.
11 - 13 - 17 - 19
75:11

25. The ratio of the areas of two similar polygons is ...
x(x - y + 1)
... the square of the ratios of the corresponding sides.
The curve opens downward and the vertex is the maximum point on the graph.
A set with a number of elements which can be counted.

26. What is a tangent?
(a - b)^2
16.6666%
A tangent is a line that only touches one point on the circumference of a circle.
3

27. To convert a decimal to a percent...
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
.0004809 X 10^11
...multiply by 100.
A reflection about the axis.

28. 10<all primes<20
55%
11 - 13 - 17 - 19
41 - 43 - 47
Members or elements

29. Can the output value of a function have more than one input value?
20.5
Sqrt 12
Yes. [i.e. f(x) = x^2 - 1
The greatest value minus the smallest.

30. Order of quadrants:
From northeast - counterclockwise. I - II - III - IV
Diameter(Pi)
Undefined
The objects within a set.

31. 5/8 in percent?
C = (pi)d
53 - 59
62.5%
... the square of the ratios of the corresponding sides.

32. What is the empty set?
A set with no members - denoted by a circle with a diagonal through it.
Even
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

33. Factor x^2 - xy + x.
x(x - y + 1)
The objects within a set.
2^9 / 2 = 256
A chord is a line segment joining two points on a circle.

34. What is a set with no members called?
No - only like radicals can be added.
An arc is a portion of a circumference of a circle.
The set of output values for a function.
The empty set - denoted by a circle with a diagonal through it.

35. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
1
31 - 37
(amount of increase/original price) x 100%
C = (pi)d

36. What is an exterior angle?
An angle which is supplementary to an interior angle.
F(x) - c
62.5%
23 - 29

37. What is the area of a regular hexagon with side 6?
Angle/360 x 2(pi)r
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
83.333%
The union of A and B.

38. Is 0 even or odd?
The overlapping sections.
Even
10! / 3!(10-3)! = 120
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

39. (a^-1)/a^5
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
The objects within a set.
1/a^6
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

40. A company places a 6-symbol code on each product. The code consists of the letter T - followed by 3 numerical digits - and then 2 consonants (Y is a conson). How many codes are possible?
An infinite set.
441000 = 1 10 10 10 21 * 21
x^(6-3) = x^3
F(x + c)

41. If 10800 is invested at a simple interest rate of 4% - what is the value of the investment after 18 months?
413.03 / 10^4 (move the decimal point 4 places to the left)
The sum of its digits is divisible by 3.
$11 -448
... the square of the ratios of the corresponding sides.

42. Evaluate 4/11 + 11/12
x^(2(4)) =x^8 = (x^4)^2
Members or elements
1 & 37/132
F(x-c)

43. What is a finite set?
500
A set with a number of elements which can be counted.
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
A = I (1 + rt)

44. What is the set of elements which can be found in either A or B?
2^9 / 2 = 256
10
The union of A and B.
413.03 / 10^4 (move the decimal point 4 places to the left)

45. What is the name for a grouping of the members within a set based on a shared characteristic?
A circle centered on the origin with radius 8.
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
9 : 25
A subset.

46. Describe the relationship between the graphs of x^2 and (1/2)x^2
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
(base*height) / 2
The second graph is less steep.
F(x + c)

47. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
The shortest arc between points A and B on a circle'S diameter.
Its last two digits are divisible by 4.
2 & 3/7
90pi

48. (6sqrt3) x (2sqrt5) =
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
Two angles whose sum is 90.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
83.333%

49. T or F? Given d -e &f =/ 0 - [(d^3)e(f^5)] / 2d(e^3) / [3(d^2)(e^3)(f^7)] / [6(e^5)(f^2)]?
0
3
48
True

50. What does scientific notation mean?
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
20.5
IV
x(x - y + 1)