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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 slope of a horizontal line?
A set with a number of elements which can be counted.
0
A = pi(r^2)
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.

2. 25^(1/2) or sqrt. 25 =
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
A circle centered at -2 - -2 with radius 3.
5 OR -5
61 - 67

3. 4.809 X 10^7 =
.0004809 X 10^11
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
55%
72

4. What is the name for a grouping of the members within a set based on a shared characteristic?
62.5%
Area of the base X height = (pi)hr^2
A subset.
48

5. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
Two angles whose sum is 180.
1 & 37/132
Cd
3sqrt4

6. 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?
1
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
10! / 3!(10-3)! = 120
A circle centered on the origin with radius 8.

7. To convert a percent to a fraction....
Divide by 100.
71 - 73 - 79
3 - -3
288 (8 9 4)

8. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
$11 -448
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
An arc is a portion of a circumference of a circle.
2 & 3/7

9. Solve the quadratic equation ax^2 + bx + c= 0
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
87.5%
3/2 - 5/3

10. 200 <_ x <_ 300. How many values of x are divisible by 5 & 8?
3
2sqrt6
27^(-4)
Sector area = (n/360) X (pi)r^2

11. What is a piecewise equation?
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
71 - 73 - 79
Angle/360 x 2(pi)r
x^(4+7) = x^11

12. Evaluate (4^3)^2
II
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
4096
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.

13. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
Relationship cannot be determined (what if x is negative?)
An isosceles right triangle.
4096
27^(-4)

14. In a regular polygon with n sides - the formula for the sum of interior angles
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...
(n-2) x 180
The curve opens upward and the vertex is the minimal point on the graph.
71 - 73 - 79

15. For what values should the domain be restricted for the function f(x) = sqrt(x + 8)
An isosceles right triangle.
8
90pi
Infinite.

16. 10<all primes<20
11 - 13 - 17 - 19
$11 -448
The interesection of A and B.
1

17. What is the absolute value function?
A circle centered at -2 - -2 with radius 3.
0
G(x) = {x}
72

18. Describe the relationship between the graphs of x^2 and (1/2)x^2
Undefined
The set of output values for a function.
18
The second graph is less steep.

19. The perimeter of a square is 48 inches. The length of its diagonal is:
12sqrt2
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
48
The set of input values for a function.

20. To convert a decimal to a percent...
IV
...multiply by 100.
II
x^(2(4)) =x^8 = (x^4)^2

21. What does scientific notation mean?
Move the decimal point to the right x places
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
The empty set - denoted by a circle with a diagonal through it.
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.

22. Whats the difference between factors and multiples?
90pi
4.25 - 6 - 22
IV
Factors are few - multiples are many.

23. What are the roots of the quadrinomial x^2 + 2x + 1?
A reflection about the axis.
The two xes after factoring.
(a - b)(a + b)
130pi

24. Order of quadrants:
From northeast - counterclockwise. I - II - III - IV
x^(2(4)) =x^8 = (x^4)^2
52
413.03 / 10^4 (move the decimal point 4 places to the left)

25. What is an exterior angle?
(base*height) / 2
An angle which is supplementary to an interior angle.
10! / 3!(10-3)! = 120
The third side is greater than the difference and less than the sum.

26. Area of a triangle?
The shortest arc between points A and B on a circle'S diameter.
(base*height) / 2
52
10! / 3!(10-3)! = 120

27. P and r are factors of 100. What is greater - pr or 100?
The sum of its digits is divisible by 3.
Undefined - because we can'T divide by 0.
Indeterminable.
13

28. Legs: 3 - 4. Hypotenuse?
5
...multiply by 100.
Cd
Two angles whose sum is 180.

29. What is a major arc?

30. 70 < all primes< 80
71 - 73 - 79
2(pi)r^2 + 2(pi)rh
3sqrt4
...multiply by 100.

31. Simplify the expression [(b^2 - c^2) / (b - c)]
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
(b + c)
27^(-4)
Arc length = (n/360) x pi(2r) where n is the number of degrees.

32. 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?
I
N! / (k!)(n-k)!
Its divisible by 2 and by 3.
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)

33. How to find the diagonal of a rectangular solid?
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
(amount of increase/original price) x 100%
The second graph is less steep.
413.03 / 10^4 (move the decimal point 4 places to the left)

34. What is a minor arc?

35. What is the graph of f(x) shifted downward c units or spaces?
13
441000 = 1 10 10 10 21 * 21
70
F(x) - c

36. What is the coefficient of the x^2 term in the product of (x + 1)(x + 2)(x -1)?
Arc length = (n/360) x pi(2r) where n is the number of degrees.
2sqrt6
55%
2

37. Evaluate 4/11 + 11/12
True
1 & 37/132
C = 2(pi)r
3/2 - 5/3

38. How to find the area of a sector?
A circle centered at -2 - -2 with radius 3.
Angle/360 x (pi)r^2
x= (1.2)(.8)lw
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

39. 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
Factors are few - multiples are many.
18
x^(4+7) = x^11
1 & 37/132

40. 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?
A = I (1 + rt)
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
All numbers multiples of 1.
10! / (10-3)! = 720

41. Which quadrant is the lower left hand?
II
C = (pi)d
x^(4+7) = x^11
III

42. Which is greater? 27^(-4) or 9^(-8)
27^(-4)
G(x) = {x}
53 - 59
x(x - y + 1)

43. 50 < all primes< 60
53 - 59
A 30-60-90 triangle.
2
The interesection of A and B.

44. What is a set with no members called?
62.5%
(p + q)/5
The empty set - denoted by a circle with a diagonal through it.
The set of elements which can be found in either A or B.

45. Factor a^2 + 2ab + b^2
(a + b)^2
Even
Relationship cannot be determined (what if x is negative?)
28. n = 8 - k = 2. n! / k!(n-k)!

46. What is the 'domain' of a function?
0
Even
The set of input values for a function.
1/2 times 7/3

47. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
When the function is not defined for all real numbers -; only a subset of the real numbers.
Two angles whose sum is 90.
70
75:11

48. x^(-y)=
A grouping of the members within a set based on a shared characteristic.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
6
1/(x^y)

49. What is an arc of a circle?
52
Ax^2 + bx + c where a -b and c are constants and a /=0
The longest arc between points A and B on a circle'S diameter.
An arc is a portion of a circumference of a circle.

50. Length of an arc of a circle?
Undefined - because we can'T divide by 0.
Sector area = (n/360) X (pi)r^2
9 & 6/7
Angle/360 x 2(pi)r