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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 name of set with a number of elements which cannot be counted?
6
1
An infinite set.
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.

2. What is the 'Range' of a function?
1:sqrt3:2
90
The set of output values for a function.
An expression with just one term (-6x - 2a^2)

3. What is the formula for compounded interest?
... the square of the ratios of the corresponding sides.
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.
N! / (k!)(n-k)!
1/2 times 7/3

4. 10<all primes<20
11 - 13 - 17 - 19
F(x-c)
...multiply by 100.
48

5. What is the sum of the angles of a triangle?
180 degrees
7 / 1000
28. n = 8 - k = 2. n! / k!(n-k)!
41 - 43 - 47

6. What percent of 40 is 22?
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.
55%
x^(6-3) = x^3
The two xes after factoring.

7. a^2 - 2ab + b^2
An angle which is supplementary to an interior angle.
2.592 kg
The direction of the inequality is reversed.
(a - b)^2

8. Evaluate (4^3)^2
The set of output values for a function.
(b + c)
No - only like radicals can be added.
4096

9. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
The overlapping sections.
1
II
An isosceles right triangle.

10. To convert a decimal to a percent...
...multiply by 100.
2.592 kg
180
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)

11. What is the slope of a horizontal line?
0
1 & 37/132
The objects within a set.
Lies opposite the greater angle

12. What is a set with no members called?
From northeast - counterclockwise. I - II - III - IV
A = I (1 + rt)
1.0843 X 10^11
The empty set - denoted by a circle with a diagonal through it.

13. Can the output value of a function have more than one input value?
31 - 37
5 OR -5
The set of elements found in both A and B.
Yes. [i.e. f(x) = x^2 - 1

14. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
Move the decimal point to the right x places
The shortest arc between points A and B on a circle'S diameter.
Cd
Part = Percent X Whole

15. What are the members or elements of a set?
The objects within a set.
C = 2(pi)r
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.

16. a^0 =
5 OR -5
27^(-4)
1
The point of intersection of the systems.

17. What are the real numbers?
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
Two angles whose sum is 90.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
All the numbers on the number line (negative - rational - irrational - decimal - integer). All the numbers on the GRE are real. (-2 - 1 - .25 - 1/2 - pi)

18. What are congruent triangles?
13
10
Triangles with same measure and same side lengths.
62.5%

19. 30< all primes<40
The curve opens upward and the vertex is the minimal point on the graph.
Indeterminable.
3sqrt4
31 - 37

20. Length of an arc of a circle?
A chord is a line segment joining two points on a circle.
The steeper the slope.
1/(x^y)
Angle/360 x 2(pi)r

21. How to find the area of a sector?
7 / 1000
Angle/360 x (pi)r^2
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
The second graph is less steep.

22. 7/8 in percent?
1 & 37/132
27^(-4)
87.5%
413.03 / 10^4 (move the decimal point 4 places to the left)

23. Write 10 -843 X 10^7 in scientific notation
I
(a - b)(a + b)
62.5%
1.0843 X 10^11

24. 5x^2 - 35x -55 = 0
12.5%
55%
500
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]

25. What is the 'domain' of a function?
N! / (n-k)!
F(x-c)
The set of input values for a function.
0

26. 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?
7 / 1000
2.592 kg
The longest arc between points A and B on a circle'S diameter.
The point of intersection of the systems.

27. Legs 6 - 8. Hypotenuse?
Angle/360 x 2(pi)r
10
16.6666%
A circle centered on the origin with radius 8.

28. a^2 - b^2 =
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
(a - b)(a + b)
1.7

29. 40 < all primes<50
5
Undefined
41 - 43 - 47
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.

30. 2sqrt4 + sqrt4 =
Sqrt 12
The set of elements found in both A and B.
3/2 - 5/3
3sqrt4

31. Describe the relationship between the graphs of x^2 and (1/2)x^2
1 & 37/132
The second graph is less steep.
9 & 6/7
11 - 13 - 17 - 19

32. Simplify (a^2 + b)^2 - (a^2 - b)^2
4a^2(b)
The shortest arc between points A and B on a circle'S diameter.
Even
The curve opens downward and the vertex is the maximum point on the graph.

33. For similar triangles - the ratio of their corresponding sides is 2:3. What is the ratio of their areas?
4096
2sqrt6
(b + c)
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

34. 0^0
1
Undefined
6
...multiply by 100.

35. 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?
10! / (10-3)! = 720
9 : 25
180 degrees
Yes - like radicals can be added/subtracted.

36. (a^-1)/a^5
1/a^6
N! / (n-k)!
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
The two xes after factoring.

37. Max and Min lengths for a side of a triangle?
The third side is greater than the difference and less than the sum.
When the function is not defined for all real numbers -; only a subset of the real numbers.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
Two angles whose sum is 180.

38. 5/6 in percent?
A reflection about the origin.
55%
No - only like radicals can be added.
83.333%

39. Define an 'expression'.
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
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)
Divide by 100.
413.03 / 10^4 (move the decimal point 4 places to the left)

40. What is the area of a regular hexagon with side 6?
6 : 1 : 2
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
(amount of increase/original price) x 100%

41. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
1/a^6
Lies opposite the greater angle
All numbers multiples of 1.
A reflection about the axis.

42. (12sqrt15) / (2sqrt5) =
Triangles with same measure and same side lengths.
27^(-4)
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
The union of A and B.

43. The larger the absolute value of the slope...
(a - b)^2
130pi
37.5%
The steeper the slope.

44. Formula for the area of a sector of a circle?
1:1:sqrt2
90 degrees
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
Sector area = (n/360) X (pi)r^2

45. Can you subtract 3sqrt4 from sqrt4?
Yes - like radicals can be added/subtracted.
130pi
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
90

46. What is a chord of a circle?
A chord is a line segment joining two points on a circle.
A circle centered at -2 - -2 with radius 3.
The sum of its digits is divisible by 3.
...multiply by 100.

47. Which is greater? 200x^295 or 10x^294?
37.5%
Relationship cannot be determined (what if x is negative?)
1
288 (8 9 4)

48. 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?
All numbers multiples of 1.
Angle/360 x 2(pi)r
75:11
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.

49. How many multiples does a given number have?
Move the decimal point to the right x places
(amount of decrease/original price) x 100%
Infinite.
71 - 73 - 79

50. Simplify 9^(1/2) X 4^3 X 2^(-6)?
The curve opens upward and the vertex is the minimal point on the graph.
Undefined
11 - 13 - 17 - 19
3