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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 a major arc?

2. Formula of rectangle where l increases by 20% and w decreases by 20%
F(x + c)
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)
The sum of digits is divisible by 9.
x= (1.2)(.8)lw

3. What is a set with no members called?
The empty set - denoted by a circle with a diagonal through it.
Move the decimal point to the right x places
x(x - y + 1)
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

4. What is the slope of a vertical line?

5. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
1/(x^y)
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
75:11
1:sqrt3:2

6. What is the set of elements which can be found in either A or B?
(n-2) x 180
... the square of the ratios of the corresponding sides.
The union of A and B.
4.25 - 6 - 22

7. 40 < all primes<50
The overlapping sections.
41 - 43 - 47
A circle centered on the origin with radius 8.
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

8. For what values should the domain be restricted for the function f(x) = sqrt(x + 8)
y = 2x^2 - 3
8
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
1/2 times 7/3

9. What is the graph of f(x) shifted upward c units or spaces?
Sqrt 12
F(x) + c
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
28. n = 8 - k = 2. n! / k!(n-k)!

10. 5 bakeries sell an average of 300 muffins per bakery per day. If 2 stop making muffins but the total muffins sold stays the same - what is the average of muffins per bakery sold among the remaining?
Its divisible by 2 and by 3.
II
500
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.

11. Which is greater? 200x^295 or 10x^294?
5
The sum of its digits is divisible by 3.
Relationship cannot be determined (what if x is negative?)
55%

12. a^2 - 2ab + b^2
A set with no members - denoted by a circle with a diagonal through it.
The objects within a set.
(a - b)^2
27^(-4)

13. 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)?
Two angles whose sum is 180.
III
y = (x + 5)/2
A reflection about the axis.

14. What is the 'domain' of a function?
500
The set of input values for a function.
6
Infinite.

15. sqrt 2(sqrt 6)=
The curve opens downward and the vertex is the maximum point on the graph.
Sqrt 12
(base*height) / 2
Angle/360 x 2(pi)r

16. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
3
Triangles with same measure and same side lengths.
A reflection about the axis.
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

17. What is the measure of an exterior angle of a regular pentagon?
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
72
Relationship cannot be determined (what if x is negative?)
1:sqrt3:2

18. What is the slope of a horizontal line?
F(x) - c
0
The direction of the inequality is reversed.
1/2 times 7/3

19. What is the 'Range' of a function?
4:5
4.25 - 6 - 22
Relationship cannot be determined (what if x is negative?)
The set of output values for a function.

20. Formula to calculate arc length?
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
31 - 37
The longest arc between points A and B on a circle'S diameter.
Arc length = (n/360) x pi(2r) where n is the number of degrees.

21. What are the smallest three prime numbers greater than 65?
8
67 - 71 - 73
The objects within a set.
The curve opens upward and the vertex is the minimal point on the graph.

22. Evaluate 4/11 + 11/12
1 & 37/132
4725
(a + b)^2
48

23. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
(a - b)(a + b)
Angle/360 x 2(pi)r
28. n = 8 - k = 2. n! / k!(n-k)!
No - only like radicals can be added.

24. The objects in a set are called two names:
Members or elements
2^9 / 2 = 256
6
Diameter(Pi)

25. 3/8 in percent?
23 - 29
37.5%
(a + b)^2
The overlapping sections.

26. Write 10 -843 X 10^7 in scientific notation
An angle which is supplementary to an interior angle.
F(x) - c
The objects within a set.
1.0843 X 10^11

27. To convert a decimal to a percent...
Even
.0004809 X 10^11
Its last two digits are divisible by 4.
...multiply by 100.

28. x^4 + x^7 =
A grouping of the members within a set based on a shared characteristic.
The shortest arc between points A and B on a circle'S diameter.
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
x^(4+7) = x^11

29. Can you add sqrt 3 and sqrt 5?
72
2 & 3/7
No - only like radicals can be added.
x(x - y + 1)

30. How to find the area of a sector?
Angle/360 x (pi)r^2
The sum of its digits is divisible by 3.
y = (x + 5)/2
1/a^6

31. Is 0 even or odd?
The empty set - denoted by a circle with a diagonal through it.
An angle which is supplementary to an interior angle.
Even
3/2 - 5/3

32. 70 < all primes< 80
71 - 73 - 79
2^9 / 2 = 256
Part = Percent X Whole
Undefined

33. Volume for a cylinder?
A set with no members - denoted by a circle with a diagonal through it.
x^(2(4)) =x^8 = (x^4)^2
11 - 13 - 17 - 19
Area of the base X height = (pi)hr^2

34. From a box of 12 candles - you are to remove 5. How many different sets of 5 candles could you remove?
4:5
1
1/(x^y)
12! / 5!7! = 792

35. To convert a percent to a fraction....
A central angle is an angle formed by 2 radii.
Divide by 100.
90 degrees
5 OR -5

36. What is the 'Restricted domain of a function'?
When the function is not defined for all real numbers -; only a subset of the real numbers.
The set of output values for a function.
y = (x + 5)/2
The sum of digits is divisible by 9.

37. Formula to find a circle'S circumference from its radius?
The longest arc between points A and B on a circle'S diameter.
12sqrt2
10! / 3!(10-3)! = 120
C = 2(pi)r

38. Length of an arc of a circle?
31 - 37
180 degrees
Angle/360 x 2(pi)r
71 - 73 - 79

39. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
37.5%
90
288 (8 9 4)
0

40. 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?
87.5%
Lies opposite the greater angle
10! / 3!(10-3)! = 120
A = pi(r^2)

41. Which quadrant is the upper left hand?
II
413.03 / 10^4 (move the decimal point 4 places to the left)
67 - 71 - 73
288 (8 9 4)

42. Convert 0.7% to a fraction.
7 / 1000
(amount of increase/original price) x 100%
A subset.
Divide by 100.

43. Reduce: 4.8 : 0.8 : 1.6
Sqrt 12
10! / 3!(10-3)! = 120
9 : 25
6 : 1 : 2

44. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
The point of intersection of the systems.
Indeterminable.
28. n = 8 - k = 2. n! / k!(n-k)!
4:5

45. 60 < all primes <70
61 - 67
Arc length = (n/360) x pi(2r) where n is the number of degrees.
Indeterminable.
...multiply by 100.

46. 5/8 in percent?
62.5%
Its divisible by 2 and by 3.
Triangles with same measure and same side lengths.
13

47. Evaluate 3& 2/7 / 1/3
9 & 6/7
2 & 3/7
IV
Lies opposite the greater angle

48. Surface area for a cylinder?
A 30-60-90 triangle.
An angle which is supplementary to an interior angle.
37.5%
2(pi)r^2 + 2(pi)rh

49. 2sqrt4 + sqrt4 =
3sqrt4
28. n = 8 - k = 2. n! / k!(n-k)!
C = 2(pi)r
130pi

50. Can the input value of a function have more than one output value (i.e. x: y - y1)?
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
No - the input value has exactly one output.
90
A reflection about the origin.