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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. a^2 - b^2 =
0
4:5
1
(a - b)(a + b)

2. 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?
83.333%
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
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
y = (x + 5)/2

3. Formula to find a circle'S circumference from its diameter?
C = (pi)d
A set with a number of elements which can be counted.
4096
When the function is not defined for all real numbers -; only a subset of the real numbers.

4. Formula for the area of a circle?
A = pi(r^2)
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
2.592 kg
III

5. What is a parabola?
83.333%
Ax^2 + bx + c where a -b and c are constants and a /=0
62.5%
The two xes after factoring.

6. What is the area of a regular hexagon with side 6?
3/2 - 5/3
12.5%
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
The set of elements which can be found in either A or B.

7. Number of degrees in a triangle
The overlapping sections.
C = (pi)d
500
180

8. Whats the difference between factors and multiples?
Cd
3
Factors are few - multiples are many.
When the function is not defined for all real numbers -; only a subset of the real numbers.

9. 5/6 in percent?
1 & 37/132
A circle centered at -2 - -2 with radius 3.
83.333%
The two xes after factoring.

10. 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?
10! / 3!(10-3)! = 120
y = (x + 5)/2
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
3 - -3

11. A triangle is inscribed in a semi circle with legs 5 and 12. What is the circumfermence of the semicircle?
The third side is greater than the difference and less than the sum.
2(pi)r^2 + 2(pi)rh
13pi / 2
2sqrt6

12. What is an isoceles triangle?
F(x + c)
Two equal sides and two equal angles.
12.5%
The shortest arc between points A and B on a circle'S diameter.

13. The number of degrees in the largest angle of a triangle inscribed in a circle - in which the diameter of the circle is one side of the triangle.
Divide by 100.
90 degrees
Its negative reciprocal. (-b/a)
4.25 - 6 - 22

14. Order of quadrants:
A chord is a line segment joining two points on a circle.
From northeast - counterclockwise. I - II - III - IV
The curve opens downward and the vertex is the maximum point on the graph.
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.

15. x^(-y)=
1/(x^y)
True
27^(-4)
A set with no members - denoted by a circle with a diagonal through it.

16. The objects in a set are called two names:
Members or elements
y = 2x^2 - 3
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)
F(x + c)

17. If the two sides of a triangle are unequal then the longer side...
1/2 times 7/3
180
Lies opposite the greater angle
0

18. What is the sum of the angles of a triangle?
The union of A and B.
1:1:sqrt2
180 degrees
5

19. What is a piecewise equation?
13pi / 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.
28. n = 8 - k = 2. n! / k!(n-k)!
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.

20. Employee X is paid 19.50 per hour no matter how many a week. Employee Y earns 18 for the first 40 and 1.5 the hourly wage for every hour after that. If both earned the same amount and worked the same in one week - how many did each work?
IV
48
1.7
A tangent is a line that only touches one point on the circumference of a circle.

21. What does the graph x^2 + y^2 = 64 look like?
2sqrt6
10! / (10-3)! = 720
18
A circle centered on the origin with radius 8.

22. The perimeter of a square is 48 inches. The length of its diagonal is:
12sqrt2
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
True
The set of output values for a function.

23. In a regular polygon with n sides - the formula for the sum of interior angles
27^(-4)
F(x-c)
$3 -500 in the 9% and $2 -500 in the 7%.
(n-2) x 180

24. Which quadrant is the lower left hand?
III
10! / (10-3)! = 720
(n-2) x 180
F(x) + c

25. What is the graph of f(x) shifted left c units or spaces?
F(x + c)
3
The union of A and B.
1:1:sqrt2

26. a^2 + 2ab + b^2
37.5%
72
(a + b)^2
1

27. Hector invested $6000. Part was invested in account with 9% simple annual interest - and the rest in account with 7% simple annual interest. If he earned $490 in the first year of these investments - how much did he invest in each account?
y = 2x^2 - 3
9 : 25
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
$3 -500 in the 9% and $2 -500 in the 7%.

28. 5/8 in percent?
5
62.5%
... the square of the ratios of the corresponding sides.
7 / 1000

29. What is a major arc?

30. What is the 'domain' of a function?
1.7
The set of input values for a function.
1
The set of output values for a function.

31. What is the 'Restricted domain of a function'?
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
Arc length = (n/360) x pi(2r) where n is the number of degrees.
When the function is not defined for all real numbers -; only a subset of the real numbers.
.0004809 X 10^11

32. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
A reflection about the axis.
IV
F(x-c)
The union of A and B.

33. 1/2 divided by 3/7 is the same as
1
13pi / 2
83.333%
1/2 times 7/3

34. A number is divisible by 3 if ...
The sum of its digits is divisible by 3.
1
No - only like radicals can be added.
The third side is greater than the difference and less than the sum.

35. What is the side length of an equilateral triangle with altitude 6?
Angle/360 x 2(pi)r
x^(4+7) = x^11
C = 2(pi)r
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...

36. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
28. n = 8 - k = 2. n! / k!(n-k)!
(a + b)^2
I
y = (x + 5)/2

37. The larger the absolute value of the slope...
II
The steeper the slope.
Undefined
A = pi(r^2)

38. a^0 =
1
2
The point of intersection of the systems.
52

39. Simplify the expression [(b^2 - c^2) / (b - c)]
Sqrt 12
(b + c)
1
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)

40. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
1/a^6
1
Divide by 100.
The longest arc between points A and B on a circle'S diameter.

41. 413.03 x 10^(-4) =
6
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
413.03 / 10^4 (move the decimal point 4 places to the left)
75:11

42. What is a finite set?
A chord is a line segment joining two points on a circle.
Relationship cannot be determined (what if x is negative?)
90
A set with a number of elements which can be counted.

43. Convert 0.7% to a fraction.
The objects within a set.
7 / 1000
IV
Cd

44. What is the 'Solution' for a set of inequalities.
An infinite set.
The overlapping sections.
48
1

45. What is the set of elements which can be found in either A or B?
1:sqrt3:2
41 - 43 - 47
The union of A and B.
x^(4+7) = x^11

46. Describe the relationship between the graphs of x^2 and (1/2)x^2
The second graph is less steep.
When the function is not defined for all real numbers -; only a subset of the real numbers.
The sum of digits is divisible by 9.
1/a^6

47. What is the name for a grouping of the members within a set based on a shared characteristic?
13
Relationship cannot be determined (what if x is negative?)
5
A subset.

48. How many 3-digit positive integers are even and do not contain the digit 4?
2 & 3/7
1.0843 X 10^11
288 (8 9 4)
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.

49. Max and Min lengths for a side of a triangle?
The third side is greater than the difference and less than the sum.
A circle centered on the origin with radius 8.
Its divisible by 2 and by 3.
G(x) = {x}

50. What are the integers?
(a + b)^2
From northeast - counterclockwise. I - II - III - IV
180
All numbers multiples of 1.