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. Circumference of a circle?
(amount of decrease/original price) x 100%
72
Diameter(Pi)
(n-2) x 180

2. If the 80th percentile of the measurements is 72degrees - about how many measurments are between 69 degrees and 72 degrees? Round your answer to the nearest tenth
The set of elements found in both A and B.
53 - 59
18
(amount of decrease/original price) x 100%

3. Simplify 9^(1/2) X 4^3 X 2^(-6)?
3
3/2 - 5/3
10! / 3!(10-3)! = 120
18

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?
The third side is greater than the difference and less than the sum.
A reflection about the origin.
10! / (10-3)! = 720
10! / 3!(10-3)! = 120

5. What is the maximum value for the function g(x) = (-2x^2) -1?
1
31 - 37
The longest arc between points A and B on a circle'S diameter.
87.5%

6. Write 10 -843 X 10^7 in scientific notation
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)
1.0843 X 10^11
All numbers multiples of 1.
Ax^2 + bx + c where a -b and c are constants and a /=0

7. When does a function automatically have a restricted domain (2)?
2sqrt6
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
62.5%
6

8. 2sqrt4 + sqrt4 =
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
4a^2(b)
F(x-c)
3sqrt4

9. What is the graph of f(x) shifted upward c units or spaces?
F(x) + c
The greatest value minus the smallest.
y = 2x^2 - 3
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

10. What is the 'Range' of a series of numbers?
The greatest value minus the smallest.
52
1
130pi

11. In a triangle where the two legs are 4 and 3 - what is the value of a line directly intersecting the middle coming from the meeting point of the two legs?
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
0
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
(p + q)/5

12. What is the graph of f(x) shifted downward c units or spaces?
F(x) - c
55%
A reflection about the axis.
x^(2(4)) =x^8 = (x^4)^2

13. Length of an arc of a circle?
70
Angle/360 x (pi)r^2
Its negative reciprocal. (-b/a)
Angle/360 x 2(pi)r

14. 10^6 has how many zeroes?
23 - 29
12.5%
Pi is the ratio of a circle'S circumference to its diameter.
6

15. To convert a percent to a fraction....
(p + q)/5
Divide by 100.
441000 = 1 10 10 10 21 * 21
The set of elements found in both A and B.

16. What is the slope of a horizontal line?
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
0
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.

17. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
500
A circle centered on the origin with radius 8.
Two angles whose sum is 180.
28. n = 8 - k = 2. n! / k!(n-k)!

18. 4.809 X 10^7 =
F(x + c)
70
.0004809 X 10^11
2.592 kg

19. 5x^2 - 35x -55 = 0
1
48
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
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

20. a^2 - b^2
(a - b)(a + b)
A chord is a line segment joining two points on a circle.
12! / 5!7! = 792
1

21. What is the empty set?
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
A set with no members - denoted by a circle with a diagonal through it.
The sum of digits is divisible by 9.
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)

22. What is the coefficient of the x^2 term in the product of (x + 1)(x + 2)(x -1)?
Even
Part = Percent X Whole
2
F(x-c)

23. Area of a triangle?
(base*height) / 2
The sum of digits is divisible by 9.
Lies opposite the greater angle
Yes - like radicals can be added/subtracted.

24. Formula to find a circle'S circumference from its diameter?
11 - 13 - 17 - 19
Lies opposite the greater angle
10! / (10-3)! = 720
C = (pi)d

25. What is the graph of f(x) shifted left c units or spaces?
6 : 1 : 2
90 degrees
A = pi(r^2)
F(x + c)

26. Formula for the area of a sector of a circle?
All numbers multiples of 1.
Sector area = (n/360) X (pi)r^2
23 - 29
4.25 - 6 - 22

27. a^2 - 2ab + b^2
(a - b)^2
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
N! / (n-k)!
An infinite set.

28. Max and Min lengths for a side of a triangle?
A = pi(r^2)
Triangles with same measure and same side lengths.
The third side is greater than the difference and less than the sum.
Two angles whose sum is 180.

29. What is the area of a regular hexagon with side 6?
7 / 1000
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
9 : 25
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

30. 3/8 in percent?
37.5%
130pi
The greatest value minus the smallest.
The shortest arc between points A and B on a circle'S diameter.

31. What does the graph (x+2)^2 + (y+2)^2 = 9 look like?
The overlapping sections.
52
A circle centered at -2 - -2 with radius 3.
16.6666%

32. a^2 - b^2 =
...multiply by 100.
10! / (10-3)! = 720
(a - b)(a + b)
1

33. What is the 'Solution' for a set of inequalities.
1.7
The overlapping sections.
A central angle is an angle formed by 2 radii.
90

34. What is a central angle?
A central angle is an angle formed by 2 radii.
F(x-c)
6
3

35. What is a tangent?
y = 2x^2 - 3
... the square of the ratios of the corresponding sides.
An infinite set.
A tangent is a line that only touches one point on the circumference of a circle.

36. What is the absolute value function?
27^(-4)
No - the input value has exactly one output.
3/2 - 5/3
G(x) = {x}

37. 10<all primes<20
11 - 13 - 17 - 19
Angle/360 x 2(pi)r
The set of output values for a function.
441000 = 1 10 10 10 21 * 21

38. A number is divisible by 3 if ...
2.592 kg
A reflection about the origin.
Relationship cannot be determined (what if x is negative?)
The sum of its digits is divisible by 3.

39. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
70
.0004809 X 10^11
A set with no members - denoted by a circle with a diagonal through it.
The shortest arc between points A and B on a circle'S diameter.

40. (12sqrt15) / (2sqrt5) =
A circle centered at -2 - -2 with radius 3.
An arc is a portion of a circumference of a circle.
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
Factors are few - multiples are many.

41. What is a set with no members called?
The empty set - denoted by a circle with a diagonal through it.
A tangent is a line that only touches one point on the circumference of a circle.
A reflection about the axis.
Lies opposite the greater angle

42. What is the 'Range' of a function?
(a - b)^2
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)
The set of output values for a function.
Move the decimal point to the right x places

43. 6w^2 - w - 15 = 0
1.0843 X 10^11
3/2 - 5/3
The two xes after factoring.
A subset.

44. What is the formula for computing simple interest?
1/(x^y)
N! / (k!)(n-k)!
A = I (1 + rt)
All numbers multiples of 1.

45. 1/2 divided by 3/7 is the same as
1/2 times 7/3
x^(2(4)) =x^8 = (x^4)^2
Factors are few - multiples are many.
A chord is a line segment joining two points on a circle.

46. In a regular polygon with n sides - the formula for the sum of interior angles
N! / (k!)(n-k)!
3sqrt4
(n-2) x 180
x^(6-3) = x^3

47. What are the smallest three prime numbers greater than 65?
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
A = I (1 + rt)
The longest arc between points A and B on a circle'S diameter.
67 - 71 - 73

48. What is the ratio of the sides of a 30-60-90 triangle?
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
(a - b)(a + b)
The curve opens downward and the vertex is the maximum point on the graph.
1:sqrt3:2

49. 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?
6
90
The objects within a set.
52

50. What is an exterior angle?
An angle which is supplementary to an interior angle.
F(x-c)
90 degrees
y = 2x^2 - 3