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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. Can the input value of a function have more than one output value (i.e. x: y - y1)?
No - the input value has exactly one output.
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
61 - 67
A central angle is an angle formed by 2 radii.

2. Describe the relationship between 3x^2 and 3(x - 1)^2
18
F(x) - c
61 - 67
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.

3. 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?
5 OR -5
90 degrees
I
2.592 kg

4. Find the surface area of a cylinder with radius 3 and height 12.
The set of elements found in both A and B.
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
The greatest value minus the smallest.
90pi

5. What is an isoceles triangle?
12! / 5!7! = 792
N! / (n-k)!
16.6666%
Two equal sides and two equal angles.

6. What is the 'union' of A and B?
The sum of its digits is divisible by 3.
The set of elements which can be found in either A or B.
20.5
A set with no members - denoted by a circle with a diagonal through it.

7. a^2 - b^2 =
.0004809 X 10^11
3 - -3
(a - b)(a + b)
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)

8. 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?
Even
An infinite set.
10! / (10-3)! = 720
62.5%

9. In a regular polygon with n sides - the formula for the sum of interior angles
(amount of decrease/original price) x 100%
Angle/360 x 2(pi)r
(n-2) x 180
N! / (k!)(n-k)!

10. What percent of 40 is 22?
Members or elements
F(x-c)
55%
A reflection about the origin.

11. Can you add sqrt 3 and sqrt 5?
9 & 6/7
G(x) = {x}
No - only like radicals can be added.
...multiply by 100.

12. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
61 - 67
Arc length = (n/360) x pi(2r) where n is the number of degrees.
2 & 3/7
13

13. Write 10 -843 X 10^7 in scientific notation
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)
1.0843 X 10^11
48
10

14. The larger the absolute value of the slope...
The steeper the slope.
62.5%
y = 2x^2 - 3
A = pi(r^2)

15. 1/2 divided by 3/7 is the same as
x^(6-3) = x^3
1/2 times 7/3
413.03 / 10^4 (move the decimal point 4 places to the left)
A central angle is an angle formed by 2 radii.

16. Max and Min lengths for a side of a triangle?
4096
The third side is greater than the difference and less than the sum.
1
A = pi(r^2)

17. Suppose that the graph of f(x) is the result of stretching y=x + 5 away from the x-axis by a factor of 2. What is the new equation for the graph f(x)?
Even
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
y = (x + 5)/2
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)

18. To multiply a number by 10^x
A reflection about the axis.
2(pi)r^2 + 2(pi)rh
Move the decimal point to the right x places
No - only like radicals can be added.

19. 1:sqrt3:2 is the ratio of the sides of what kind of triangle?
4.25 - 6 - 22
A 30-60-90 triangle.
Members or elements
1/2 times 7/3

20. If a=-1 and b=3 - what is the value of (4(a^3)(b^2) - 12(a^2)(b^5)) / (16(a^3)(b^2))?
An isosceles right triangle.
7 / 1000
2sqrt6
20.5

21. If Madagascar'S exports totaled 1.3 billion in 2009 - and 4% came from China - what was the value in millions of the country'S exports to China?
288 (8 9 4)
52
The union of A and B.
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

22. Can you simplify sqrt72?
y = (x + 5)/2
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
1.0843 X 10^11
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

23. What are congruent triangles?
500
Triangles with same measure and same side lengths.
A subset.
1/a^6

24. How to determine percent increase?
The union of A and B.
An expression with just one term (-6x - 2a^2)
(amount of increase/original price) x 100%
4.25 - 6 - 22

25. Circumference of a circle?
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
Diameter(Pi)
(p + q)/5
55%

26. Which is greater? 64^5 or 16^8
0
II
True
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

27. Can you subtract 3sqrt4 from sqrt4?
From northeast - counterclockwise. I - II - III - IV
... the square of the ratios of the corresponding sides.
Yes - like radicals can be added/subtracted.
x^(2(4)) =x^8 = (x^4)^2

28. 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?
Yes. [i.e. f(x) = x^2 - 1
441000 = 1 10 10 10 21 * 21
A tangent is a line that only touches one point on the circumference of a circle.
y = 2x^2 - 3

29. How many 3-digit positive integers are even and do not contain the digit 4?
$3 -500 in the 9% and $2 -500 in the 7%.
The longest arc between points A and B on a circle'S diameter.
1
288 (8 9 4)

30. 5x^2 - 35x -55 = 0
52
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
4.25 - 6 - 22
9 : 25

31. Order of quadrants:
From northeast - counterclockwise. I - II - III - IV
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
Indeterminable.

32. The objects in a set are called two names:
10
1/(x^y)
Members or elements
4.25 - 6 - 22

33. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
90
F(x-c)
0
28. n = 8 - k = 2. n! / k!(n-k)!

34. What is the 'Solution' for a system of linear equations?
The greatest value minus the smallest.
Part = Percent X Whole
The point of intersection of the systems.
The interesection of A and B.

35. 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)]?
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
True
Lies opposite the greater angle
4725

36. Reduce: 4.8 : 0.8 : 1.6
Sector area = (n/360) X (pi)r^2
A set with a number of elements which can be counted.
y = 2x^2 - 3
6 : 1 : 2

37. 2sqrt4 + sqrt4 =
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
The curve opens upward and the vertex is the minimal point on the graph.
3sqrt4
An isosceles right triangle.

38. Factor a^2 + 2ab + b^2
C = 2(pi)r
A = I (1 + rt)
(a + b)^2
90 degrees

39. 20<all primes<30
A = I (1 + rt)
23 - 29
III
Arc length = (n/360) x pi(2r) where n is the number of degrees.

40. What is it called when a point is reflected to the quadrant opposite it (i.e. I to III or II to IV)?
A reflection about the origin.
The third side is greater than the difference and less than the sum.
A tangent is a line that only touches one point on the circumference of a circle.
8

41. Formula for the area of a circle?
A = pi(r^2)
x(x - y + 1)
A subset.
Yes. [i.e. f(x) = x^2 - 1

42. What is the 'Range' of a function?
A set with a number of elements which can be counted.
An infinite set.
A = I (1 + rt)
The set of output values for a function.

43. What is the formula for computing simple interest?
A = I (1 + rt)
Factors are few - multiples are many.
No - only like radicals can be added.
True

44. What is the area of a regular hexagon with side 6?
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)
130pi
0
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

45. The slope of a line perpendicular to (a/b)?
4a^2(b)
10! / (10-3)! = 720
Its negative reciprocal. (-b/a)
Divide by 100.

46. Can the output value of a function have more than one input value?
Yes. [i.e. f(x) = x^2 - 1
4.25 - 6 - 22
The sum of its digits is divisible by 3.
Ax^2 + bx + c where a -b and c are constants and a /=0

47. What is the intersection of A and B?
The set of elements found in both A and B.
62.5%
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
Even

48. What is the absolute value function?
G(x) = {x}
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)
1

49. Which quadrant is the upper right hand?
I
11 - 13 - 17 - 19
12.5%
180 degrees

50. (a^-1)/a^5
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)
1 & 37/132
41 - 43 - 47
1/a^6