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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 'Range' of a series of numbers?
The greatest value minus the smallest.
52
Area of the base X height = (pi)hr^2
(a + b)^2

2. To convert a percent to a fraction....
x(x - y + 1)
41 - 43 - 47
90 degrees
Divide by 100.

3. a^2 - b^2
(a - b)(a + b)
From northeast - counterclockwise. I - II - III - IV
12! / 5!7! = 792
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

4. A number is divisible by 4 is...
18
0
...multiply by 100.
Its last two digits are divisible by 4.

5. Convert 0.7% to a fraction.
The curve opens downward and the vertex is the maximum point on the graph.
7 / 1000
y = (x + 5)/2
x(x - y + 1)

6. Number of degrees in a triangle
180
x^(6-3) = x^3
Divide by 100.
No - the input value has exactly one output.

7. What is the graph of f(x) shifted left c units or spaces?
4.25 - 6 - 22
F(x + c)
F(x) - c
(a - b)^2

8. Order of quadrants:
From northeast - counterclockwise. I - II - III - IV
x= (1.2)(.8)lw
The set of output values for a function.
0

9. What is an arc of a circle?
An arc is a portion of a circumference of a circle.
1
Infinite.
Pi is the ratio of a circle'S circumference to its diameter.

10. Which quadrant is the lower left hand?
...multiply by 100.
III
(a + b)^2
67 - 71 - 73

11. Formula of rectangle where l increases by 20% and w decreases by 20%
27^(-4)
x= (1.2)(.8)lw
The interesection of A and B.
y = 2x^2 - 3

12. 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?
y = 2x^2 - 3
10! / (10-3)! = 720
The greatest value minus the smallest.
Part = Percent X Whole

13. What is the 'Solution' for a system of linear equations?
All numbers multiples of 1.
441000 = 1 10 10 10 21 * 21
The point of intersection of the systems.
Part = Percent X Whole

14. 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?
67 - 71 - 73
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
Undefined
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

15. 30< all primes<40
... the square of the ratios of the corresponding sides.
31 - 37
(base*height) / 2
Cd

16. What are complementary angles?
Two angles whose sum is 90.
C = (pi)d
x(x - y + 1)
2.592 kg

17. Formula to find a circle'S circumference from its diameter?
A reflection about the axis.
1/(x^y)
Sqrt 12
C = (pi)d

18. 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.
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
0
2 & 3/7

19. 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?
6 : 1 : 2
31 - 37
7 / 1000
10! / 3!(10-3)! = 120

20. 60 < all primes <70
61 - 67
x= (1.2)(.8)lw
Two angles whose sum is 180.
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

21. How to find the area of a sector?
Angle/360 x (pi)r^2
Area of the base X height = (pi)hr^2
The interesection of A and B.
A circle centered at -2 - -2 with radius 3.

22. Which is greater? 27^(-4) or 9^(-8)
.0004809 X 10^11
9 : 25
27^(-4)
When the function is not defined for all real numbers -; only a subset of the real numbers.

23. 5 bakeries sell an average of 300 muffins per bakery per day. If 2 stop making muffins but the total muffins sold stays the same - what is the average of muffins per bakery sold among the remaining?
Even
70
500
1

24. 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)]?
True
The direction of the inequality is reversed.
$11 -448
An expression with just one term (-6x - 2a^2)

25. Can you simplify sqrt72?
90pi
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
6 : 1 : 2
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.

26. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
75:11
Ax^2 + bx + c where a -b and c are constants and a /=0
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)

27. Which quadrant is the upper left hand?
II
The overlapping sections.
A tangent is a line that only touches one point on the circumference of a circle.
(amount of decrease/original price) x 100%

28. A triangle is inscribed in a semi circle with legs 5 and 12. What is the circumfermence of the semicircle?
413.03 / 10^4 (move the decimal point 4 places to the left)
The direction of the inequality is reversed.
13pi / 2
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

29. What are congruent triangles?
I
The steeper the slope.
Triangles with same measure and same side lengths.
55%

30. When the 'a' in the parabola is negative...
1.0843 X 10^11
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)
IV
The curve opens downward and the vertex is the maximum point on the graph.

31. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
12.5%
1
A reflection about the axis.

32. What does the graph x^2 + y^2 = 64 look like?
90pi
Yes. [i.e. f(x) = x^2 - 1
A circle centered on the origin with radius 8.
Divide by 100.

33. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
0
1
x^(6-3) = x^3
F(x + c)

34. What is a tangent?
Yes. [i.e. f(x) = x^2 - 1
A tangent is a line that only touches one point on the circumference of a circle.
16.6666%
An isosceles right triangle.

35. Area of a triangle?
2sqrt6
12sqrt2
(base*height) / 2
(a + b)^2

36. Which is greater? 200x^295 or 10x^294?
The point of intersection of the systems.
55%
Relationship cannot be determined (what if x is negative?)
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]

37. What is the set of elements found in both A and B?
8
A subset.
II
The interesection of A and B.

38. Simplify 4sqrt21 X 5sqrt2 / 10sqrt7
2sqrt6
48
9 & 6/7
The shortest arc between points A and B on a circle'S diameter.

39. a^2 + 2ab + b^2
1:sqrt3:2
(a + b)^2
1
31 - 37

40. When the 'a' in a parabola is positive....
$11 -448
The set of elements which can be found in either A or B.
10
The curve opens upward and the vertex is the minimal point on the graph.

41. The objects in a set are called two names:
An angle which is supplementary to an interior angle.
1.0843 X 10^11
Members or elements
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

42. A number is divisible by 9 if...
The sum of digits is divisible by 9.
The shortest arc between points A and B on a circle'S diameter.
An angle which is supplementary to an interior angle.
Two equal sides and two equal angles.

43. Is 0 even or odd?
Even
C = 2(pi)r
1:sqrt3:2
From northeast - counterclockwise. I - II - III - IV

44. Factor a^2 + 2ab + b^2
1
(a + b)^2
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
An algebraic expression is a combination of one of more terms. Terms in an expression are separated by either addition or subtraction signs. (3xy - 4ab - -5cd - x^2 + x - 1)

45. A number is divisible by 6 if...
4725
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.
Its divisible by 2 and by 3.
A 30-60-90 triangle.

46. What is the graph of f(x) shifted upward c units or spaces?
6
No - only like radicals can be added.
F(x) + c
IV

47. Formula to find a circle'S circumference from its radius?
3sqrt4
C = 2(pi)r
A circle centered on the origin with radius 8.
130pi

48. Find the surface area of a cylinder with radius 3 and height 12.
90pi
The set of input values for a function.
87.5%
The objects within a set.

49. What is the sum of the angles of a triangle?
180 degrees
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
61 - 67
The shortest arc between points A and B on a circle'S diameter.

50. What are the integers?
Its negative reciprocal. (-b/a)
Arc length = (n/360) x pi(2r) where n is the number of degrees.
An infinite set.
All numbers multiples of 1.