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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. Describe the relationship between 3x^2 and 3(x - 1)^2
C = 2(pi)r
Its last two digits are divisible by 4.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
The shortest arc between points A and B on a circle'S diameter.

2. Can the output value of a function have more than one input value?
1
Yes. [i.e. f(x) = x^2 - 1
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
(a + b)^2

3. Formula for the area of a sector of a circle?
.0004809 X 10^11
III
Sector area = (n/360) X (pi)r^2
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)

4. What is the name for a grouping of the members within a set based on a shared characteristic?
87.5%
1
11 - 13 - 17 - 19
A subset.

5. What is the graph of f(x) shifted right c units or spaces?
Diameter(Pi)
.0004809 X 10^11
F(x-c)
Two angles whose sum is 180.

6. What percent of 40 is 22?
55%
(b + c)
Yes - like radicals can be added/subtracted.
16.6666%

7. What is the ratio of the sides of a 30-60-90 triangle?
Sector area = (n/360) X (pi)r^2
The set of elements which can be found in either A or B.
The curve opens downward and the vertex is the maximum point on the graph.
1:sqrt3:2

8. A cylinder has surface area 22pi. If the cylinder has a height of 10 - what is its radius?
Angle/360 x 2(pi)r
Divide by 100.
1:sqrt3:2
1

9. 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)]?
67 - 71 - 73
The curve opens upward and the vertex is the minimal point on the graph.
II
True

10. What is the graph of f(x) shifted left c units or spaces?
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 - b)^2
F(x + c)
A subset.

11. Suppose you have a set of n objects - and you want to select k of them - but the order doesn'T matter. What formula do you use to determine the number of combinations of n objects taken k at a time?
N! / (k!)(n-k)!
The set of output values for a function.
The set of elements which can be found in either A or B.
9 & 6/7

12. 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)!
.0004809 X 10^11
F(x-c)
An infinite set.

13. If an inequality is multiplied or divided by a negative number....
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 direction of the inequality is reversed.
Two angles whose sum is 90.
Yes - like radicals can be added/subtracted.

14. Can you simplify sqrt72?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
The two xes after factoring.
A = I (1 + rt)
The direction of the inequality is reversed.

15. What is the graph of f(x) shifted downward c units or spaces?
87.5%
F(x) - c
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
1 & 37/132

16. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
1
C = 2(pi)r
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.
F(x + c)

17. Legs 5 - 12. Hypotenuse?
4096
4.25 - 6 - 22
90
13

18. Evaluate (4^3)^2
I
4096
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
1

19. 200 <_ x <_ 300. How many values of x are divisible by 5 & 8?
III
The set of elements found in both A and B.
3
Angle/360 x (pi)r^2

20. Formula to find a circle'S circumference from its radius?
IV
Indeterminable.
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)
C = 2(pi)r

21. 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?
(a + b)^2
12! / 5!7! = 792
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
No - the input value has exactly one output.

22. Define an 'expression'.
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)
The interesection of A and B.
71 - 73 - 79
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)

23. Which quadrant is the lower left hand?
III
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)
No - only like radicals can be added.
1/2 times 7/3

24. 1:sqrt3:2 is the ratio of the sides of what kind of triangle?
Angle/360 x (pi)r^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.
The longest arc between points A and B on a circle'S diameter.
A 30-60-90 triangle.

25. Convert 0.7% to a fraction.
The overlapping sections.
7 / 1000
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

26. How many multiples does a given number have?
180 degrees
10! / 3!(10-3)! = 120
Diameter(Pi)
Infinite.

27. What is the percent formula?
N! / (k!)(n-k)!
N! / (n-k)!
Undefined
Part = Percent X Whole

28. 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.
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
N! / (n-k)!
A reflection about the origin.

29. What is the set of elements found in both A and B?
F(x) - c
1.0843 X 10^11
(a + b)^2
The interesection of A and B.

30. What is an isoceles triangle?
Two equal sides and two equal angles.
Its last two digits are divisible by 4.
62.5%
(p + q)/5

31. What does the graph x^2 + y^2 = 64 look like?
2^9 / 2 = 256
Ax^2 + bx + c where a -b and c are constants and a /=0
288 (8 9 4)
A circle centered on the origin with radius 8.

32. Area of a triangle?
N! / (n-k)!
(b + c)
4:5
(base*height) / 2

33. 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?
48
500
3/2 - 5/3
72

34. What is a piecewise equation?
3
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
A = pi(r^2)

35. How to find the area of a sector?
1/2 times 7/3
The direction of the inequality is reversed.
Angle/360 x (pi)r^2
72

36. The ratio of the areas of two similar polygons is ...
... the square of the ratios of the corresponding sides.
37.5%
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
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

37. 30< all primes<40
31 - 37
3/2 - 5/3
Two angles whose sum is 180.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).

38. What is a central angle?
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).
... the square of the ratios of the corresponding sides.
3

39. 6w^2 - w - 15 = 0
3/2 - 5/3
y = (x + 5)/2
2^9 / 2 = 256
No - the input value has exactly one output.

40. When the 'a' in a parabola is positive....
5
x^(6-3) = x^3
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
The curve opens upward and the vertex is the minimal point on the graph.

41. Volume for a cylinder?
Area of the base X height = (pi)hr^2
2.592 kg
(amount of decrease/original price) x 100%
13

42. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
Area of the base X height = (pi)hr^2
The set of input values for a function.
(p + q)/5
4725

43. 1/6 in percent?
Lies opposite the greater angle
16.6666%
1:1:sqrt2
2

44. What are 'Supplementary angles?'
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
28. n = 8 - k = 2. n! / k!(n-k)!
Two angles whose sum is 180.
7 / 1000

45. Write 10 -843 X 10^7 in scientific notation
1/a^6
1.0843 X 10^11
10
y = 2x^2 - 3

46. What is the 'Range' of a series of numbers?
12.5%
The greatest value minus the smallest.
A reflection about the origin.
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)

47. (6sqrt3) x (2sqrt5) =
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
0
75:11
A chord is a line segment joining two points on a circle.

48. How many 3-digit positive integers are even and do not contain the digit 4?
A = pi(r^2)
288 (8 9 4)
1
2.592 kg

49. The perimeter of a square is 48 inches. The length of its diagonal is:
0
12sqrt2
(a + b)^2
Two angles whose sum is 180.

50. Simplify (a^2 + b)^2 - (a^2 - b)^2
The objects within a set.
C = (pi)d
C = 2(pi)r
4a^2(b)