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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. Factor a^2 + 2ab + b^2
The empty set - denoted by a circle with a diagonal through it.
31 - 37
(a + b)^2
Infinite.

2. What is the absolute value function?
G(x) = {x}
An angle which is supplementary to an interior angle.
The curve opens downward and the vertex is the maximum point on the graph.
A grouping of the members within a set based on a shared characteristic.

3. What is it called when a point is reflected to the quadrant opposite it (i.e. I to III or II to IV)?
10! / (10-3)! = 720
A reflection about the origin.
1 & 37/132
The set of elements found in both A and B.

4. x^6 / x^3
x^(6-3) = x^3
180
1
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)

5. When the 'a' in the parabola is negative...
2.592 kg
6
90pi
The curve opens downward and the vertex is the maximum point on the graph.

6. Surface area for a cylinder?
Triangles with same measure and same side lengths.
9 : 25
2(pi)r^2 + 2(pi)rh
90 degrees

7. 3/8 in percent?
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 arc is a portion of a circumference of a circle.
37.5%
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]

8. How many 3-digit positive integers are even and do not contain the digit 4?
2^9 / 2 = 256
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
288 (8 9 4)
The union of A and B.

9. A brick with dimensions 10. 15 and 25 weighs 1.5 kg. A second brick (same density) has dimensions 12 - 18 - and 30. What is the weight of the second brick?
72
2.592 kg
An angle which is supplementary to an interior angle.
The set of elements which can be found in either A or B.

10. 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)]?
(a - b)(a + b)
True
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
Its last two digits are divisible by 4.

11. 5/8 in percent?
A tangent is a line that only touches one point on the circumference of a circle.
F(x) - c
62.5%
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.

12. 70 < all primes< 80
0
Undefined
71 - 73 - 79
70

13. Legs 5 - 12. Hypotenuse?
130pi
1:1:sqrt2
13
37.5%

14. Formula for the area of a sector of a circle?
Undefined
...multiply by 100.
A grouping of the members within a set based on a shared characteristic.
Sector area = (n/360) X (pi)r^2

15. How to determine percent decrease?
53 - 59
(amount of decrease/original price) x 100%
The set of output values for a function.
F(x-c)

16. What is the ratio of the sides of an isosceles right triangle?
Relationship cannot be determined (what if x is negative?)
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
(a - b)^2
1:1:sqrt2

17. What is the formula for computing simple interest?
An angle which is supplementary to an interior angle.
A grouping of the members within a set based on a shared characteristic.
55%
A = I (1 + rt)

18. Legs 6 - 8. Hypotenuse?
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
10
87.5%
11 - 13 - 17 - 19

19. How many digits are there between the decimal point and the first even digit in the decimal equivalent of 1/[(2^8)(5^3)]
6
Pi is the ratio of a circle'S circumference to its diameter.
0
... the square of the ratios of the corresponding sides.

20. Simplify the expression [(b^2 - c^2) / (b - c)]
The curve opens downward and the vertex is the maximum point on the graph.
A = pi(r^2)
(b + c)
83.333%

21. What is the graph of f(x) shifted upward c units or spaces?
1 & 37/132
Sector area = (n/360) X (pi)r^2
F(x) + c
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

22. What are the roots of the quadrinomial x^2 + 2x + 1?
Sector area = (n/360) X (pi)r^2
11 - 13 - 17 - 19
6
The two xes after factoring.

23. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
2 & 3/7
x^(6-3) = x^3
F(x) + c
A central angle is an angle formed by 2 radii.

24. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
A grouping of the members within a set based on a shared characteristic.
When the function is not defined for all real numbers -; only a subset of the real numbers.
Part = Percent X Whole
Cd

25. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
9 : 25
x(x - y + 1)
6 : 1 : 2
4725

26. Formula to find a circle'S circumference from its radius?
When the function is not defined for all real numbers -; only a subset of the real numbers.
20.5
C = 2(pi)r
(base*height) / 2

27. What is a set with no members called?
The empty set - denoted by a circle with a diagonal through it.
13pi / 2
The curve opens upward and the vertex is the minimal point on the graph.
4a^2(b)

28. What is the area of a regular hexagon with side 6?
2(pi)r^2 + 2(pi)rh
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
Undefined
3 - -3

29. a^2 - b^2
I
A 30-60-90 triangle.
(a - b)(a + b)
23 - 29

30. a^2 + 2ab + b^2
(a + b)^2
2^9 / 2 = 256
A 30-60-90 triangle.
61 - 67

31. What is the ratio of the sides of a 30-60-90 triangle?
1:sqrt3:2
53 - 59
10! / (10-3)! = 720
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

32. What is the name of set with a number of elements which cannot be counted?
An infinite set.
180
The overlapping sections.
The set of output values for a function.

33. From a box of 12 candles - you are to remove 5. How many different sets of 5 candles could you remove?
Two equal sides and two equal angles.
An isosceles right triangle.
67 - 71 - 73
12! / 5!7! = 792

34. (-1)^2 =
1
True
x^(2(4)) =x^8 = (x^4)^2
9 : 25

35. A number is divisible by 4 is...
71 - 73 - 79
Its last two digits are divisible by 4.
0
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.

36. How many multiples does a given number have?
Infinite.
All numbers multiples of 1.
(n-2) x 180
An expression with just one term (-6x - 2a^2)

37. Evaluate 3& 2/7 / 1/3
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
9 & 6/7
The interesection of A and B.
10! / 3!(10-3)! = 120

38. What is the percent formula?
The overlapping sections.
8
Part = Percent X Whole
y = 2x^2 - 3

39. What is a central angle?
A subset.
IV
6
A central angle is an angle formed by 2 radii.

40. The perimeter of a square is 48 inches. The length of its diagonal is:
62.5%
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
12sqrt2
G(x) = {x}

41. What is a subset?
x^(6-3) = x^3
F(x + c)
The set of elements found in both A and B.
A grouping of the members within a set based on a shared characteristic.

42. The larger the absolute value of the slope...
4a^2(b)
The set of elements found in both A and B.
The steeper the slope.
A 30-60-90 triangle.

43. Write 10 -843 X 10^7 in scientific notation
67 - 71 - 73
13pi / 2
1.0843 X 10^11
The steeper the slope.

44. Find the surface area of a cylinder with radius 3 and height 12.
Indeterminable.
90pi
x= (1.2)(.8)lw
The shortest arc between points A and B on a circle'S diameter.

45. What is the graph of f(x) shifted right c units or spaces?
F(x + c)
12sqrt2
F(x-c)
Sector area = (n/360) X (pi)r^2

46. To multiply a number by 10^x
9 : 25
1 & 37/132
The steeper the slope.
Move the decimal point to the right x places

47. What are complementary angles?
A reflection about the axis.
The curve opens downward and the vertex is the maximum point on the graph.
Two angles whose sum is 90.
The longest arc between points A and B on a circle'S diameter.

48. Solve the quadratic equation ax^2 + bx + c= 0
1 & 37/132
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
413.03 / 10^4 (move the decimal point 4 places to the left)

49. 7/8 in percent?
All numbers multiples of 1.
87.5%
(p + q)/5
(b + c)

50. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
A reflection about the axis.
A set with no members - denoted by a circle with a diagonal through it.
The set of elements found in both A and B.
C = (pi)d