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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. 60 < all primes <70
A grouping of the members within a set based on a shared characteristic.
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)
The overlapping sections.
61 - 67

2. Order of quadrants:
From northeast - counterclockwise. I - II - III - IV
4725
F(x + c)
500

3. Define a 'monomial'
1
1/a^6
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
An expression with just one term (-6x - 2a^2)

4. To convert a percent to a fraction....
(a + b)^2
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
Its divisible by 2 and by 3.
Divide by 100.

5. 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?
180 degrees
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 = 2x^2 - 3
F(x + c)

6. (a^-1)/a^5
F(x-c)
1/a^6
31 - 37
55%

7. The ratio of the areas of two similar polygons is ...
3
Sector area = (n/360) X (pi)r^2
18
... the square of the ratios of the corresponding sides.

8. (-1)^2 =
1
3/2 - 5/3
An expression with just one term (-6x - 2a^2)
Lies opposite the greater angle

9. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
The greatest value minus the smallest.
4:5
Sector area = (n/360) X (pi)r^2
4a^2(b)

10. Evaluate 4/11 + 11/12
1 & 37/132
No - the input value has exactly one output.
62.5%
1

11. (x^2)^4
The curve opens upward and the vertex is the minimal point on the graph.
x^(2(4)) =x^8 = (x^4)^2
x^(4+7) = x^11
72

12. Define an 'expression'.
3
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)
Triangles with same measure and same side lengths.
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.

13. What is a central angle?
A central angle is an angle formed by 2 radii.
IV
Arc length = (n/360) x pi(2r) where n is the number of degrees.
62.5%

14. Volume for a cylinder?
Area of the base X height = (pi)hr^2
A chord is a line segment joining two points on a circle.
413.03 / 10^4 (move the decimal point 4 places to the left)
x^(2(4)) =x^8 = (x^4)^2

15. What is the 'Restricted domain of a function'?
The point of intersection of the systems.
A = pi(r^2)
When the function is not defined for all real numbers -; only a subset of the real numbers.
A reflection about the origin.

16. What is the 'union' of A and B?
10
The set of elements which can be found in either A or B.
Triangles with same measure and same side lengths.
F(x-c)

17. How to find the circumference of a circle which circumscribes a square?
The sum of digits is divisible by 9.
A central angle is an angle formed by 2 radii.
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
Pi is the ratio of a circle'S circumference to its diameter.

18. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
The two xes after factoring.
4725
53 - 59
90

19. Define a 'Term' -
The shortest arc between points A and B on a circle'S diameter.
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)
A subset.
x(x - y + 1)

20. If r - t - s & u are distinct - consecutive prime numbers - less than 31 - which of the following could be an average of them (4 - 4.25 - 6 - 9 - 24 - 22 - 24)
4.25 - 6 - 22
31 - 37
90 degrees
288 (8 9 4)

21. x^(-y)=
23 - 29
10! / 3!(10-3)! = 120
1/(x^y)
Divide by 100.

22. Simplify 9^(1/2) X 4^3 X 2^(-6)?
x^(6-3) = x^3
3
An isosceles right triangle.
Pi is the ratio of a circle'S circumference to its diameter.

23. What is the 'Solution' for a system of linear equations?
Undefined
The point of intersection of the systems.
18
16.6666%

24. How to find the diagonal of a rectangular solid?
A central angle is an angle formed by 2 radii.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
6 : 1 : 2
2 & 3/7

25. What is the ratio of the sides of a 30-60-90 triangle?
The sum of digits is divisible by 9.
10
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...
1:sqrt3:2

26. What is the name for a grouping of the members within a set based on a shared characteristic?
90pi
Lies opposite the greater angle
A subset.
The interesection of A and B.

27. What percent of 40 is 22?
2
The set of elements which can be found in either A or B.
55%
Infinite.

28. What is the area of a regular hexagon with side 6?
The set of output values for a function.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
Undefined - because we can'T divide by 0.
1/a^6

29. 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?
y = (x + 5)/2
48
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
1

30. 0^0
y = (x + 5)/2
Undefined
The set of output values for a function.
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)

31. Formula to calculate arc length?
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)
An isosceles right triangle.
Divide by 100.
Arc length = (n/360) x pi(2r) where n is the number of degrees.

32. A number is divisible by 4 is...
... the square of the ratios of the corresponding sides.
Its last two digits are divisible by 4.
10
The two xes after factoring.

33. Evaluate 3& 2/7 / 1/3
C = (pi)d
F(x-c)
9 & 6/7
IV

34. Is 0 even or odd?
II
6
Even
The set of elements which can be found in either A or B.

35. x^2 = 9. What is the value of x?
288 (8 9 4)
3 - -3
55%
13

36. What is the side length of an equilateral triangle with altitude 6?
x^(4+7) = x^11
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...
67 - 71 - 73
An arc is a portion of a circumference of a circle.

37. Which is greater? 200x^295 or 10x^294?
Relationship cannot be determined (what if x is negative?)
G(x) = {x}
F(x) + c
9 : 25

38. Simplify the expression (p^2 - q^2)/ -5(q - p)
10! / (10-3)! = 720
All numbers multiples of 1.
441000 = 1 10 10 10 21 * 21
(p + q)/5

39. A company places a 6-symbol code on each product. The code consists of the letter T - followed by 3 numerical digits - and then 2 consonants (Y is a conson). How many codes are possible?
441000 = 1 10 10 10 21 * 21
3 - -3
70
52

40. 5/8 in percent?
A = I (1 + rt)
62.5%
x(x - y + 1)
1/(x^y)

41. What number between 70 & 75 - inclusive - has the greatest number of factors?
x^(4+7) = x^11
1:sqrt3:2
72
(amount of decrease/original price) x 100%

42. What is a tangent?
72
(amount of decrease/original price) x 100%
Part = Percent X Whole
A tangent is a line that only touches one point on the circumference of a circle.

43. Reduce: 4.8 : 0.8 : 1.6
The second graph is less steep.
Members or elements
6 : 1 : 2
C = (pi)d

44. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
5
90pi
No - only like radicals can be added.
Cd

45. What are congruent triangles?
A grouping of the members within a set based on a shared characteristic.
6
Triangles with same measure and same side lengths.
18

46. 10<all primes<20
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
90 degrees
11 - 13 - 17 - 19
Its negative reciprocal. (-b/a)

47. What is the name of set with a number of elements which cannot be counted?
Diameter(Pi)
x^(4+7) = x^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)
An infinite set.

48. How many 3-digit positive integers are even and do not contain the digit 4?
13pi / 2
288 (8 9 4)
3
72

49. Which quadrant is the upper right hand?
70
I
The curve opens downward and the vertex is the maximum point on the graph.
6 : 1 : 2

50. 7/8 in percent?
87.5%
Yes - like radicals can be added/subtracted.
(a - b)(a + b)
The curve opens upward and the vertex is the minimal point on the graph.