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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. 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?
61 - 67
48
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
4a^2(b)

2. What is the 'Restricted domain of a function'?
72
Yes - like radicals can be added/subtracted.
When the function is not defined for all real numbers -; only a subset of the real numbers.
An expression with just one term (-6x - 2a^2)

3. 60 < all primes <70
3sqrt4
x^(4+7) = x^11
61 - 67
(12/2) x (sqrt15 / sqrt5) = 6sqrt3

4. What is the ratio of the sides of a 30-60-90 triangle?
1:sqrt3:2
Sector area = (n/360) X (pi)r^2
180
x^(2(4)) =x^8 = (x^4)^2

5. Describe the relationship between the graphs of x^2 and (1/2)x^2
28. n = 8 - k = 2. n! / k!(n-k)!
90
The second graph is less steep.
20.5

6. Whats the difference between factors and multiples?
The overlapping sections.
Factors are few - multiples are many.
$11 -448
The curve opens upward and the vertex is the minimal point on the graph.

7. What is an isoceles triangle?
Members or elements
Two equal sides and two equal angles.
1.7
83.333%

8. What is the empty set?
A grouping of the members within a set based on a shared characteristic.
Yes - like radicals can be added/subtracted.
67 - 71 - 73
A set with no members - denoted by a circle with a diagonal through it.

9. Evaluate 4/11 + 11/12
1.7
1 & 37/132
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)
$11 -448

10. 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?
$3 -500 in the 9% and $2 -500 in the 7%.
A set with a number of elements which can be counted.
A reflection about the axis.
From northeast - counterclockwise. I - II - III - IV

11. Reduce: 4.8 : 0.8 : 1.6
An isosceles right triangle.
G(x) = {x}
6 : 1 : 2
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.

12. 1/8 in percent?
12.5%
1
5
$11 -448

13. How to find the area of a sector?
Angle/360 x (pi)r^2
x= (1.2)(.8)lw
(a - b)(a + b)
x^(4+7) = x^11

14. Which quadrant is the upper left hand?
True
II
A tangent is a line that only touches one point on the circumference of a circle.
48

15. a^2 - b^2 =
1 & 37/132
(a - b)(a + b)
12.5%
71 - 73 - 79

16. Can you subtract 3sqrt4 from sqrt4?
Two angles whose sum is 90.
Yes - like radicals can be added/subtracted.
The greatest value minus the smallest.
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.

17. Can the input value of a function have more than one output value (i.e. x: y - y1)?
3/2 - 5/3
13
(b + c)
No - the input value has exactly one output.

18. Convert 0.7% to a fraction.
Its last two digits are divisible by 4.
... the square of the ratios of the corresponding sides.
7 / 1000
Factors are few - multiples are many.

19. How to find the diagonal of a rectangular solid?
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
3/2 - 5/3
Triangles with same measure and same side lengths.
Undefined - because we can'T divide by 0.

20. What is it called when a point is reflected to the quadrant opposite it (i.e. I to III or II to IV)?
180
The shortest arc between points A and B on a circle'S diameter.
Two angles whose sum is 180.
A reflection about the origin.

21. 5x^2 - 35x -55 = 0
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
4a^2(b)
III
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...

22. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
4:5
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
28. n = 8 - k = 2. n! / k!(n-k)!
...multiply by 100.

23. What number between 70 & 75 - inclusive - has the greatest number of factors?
1 & 37/132
Its last two digits are divisible by 4.
72
III

24. What is the maximum value for the function g(x) = (-2x^2) -1?
1
2 & 3/7
G(x) = {x}
x^(6-3) = x^3

25. To convert a percent to a fraction....
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
Divide by 100.
The union of A and B.

26. Simplify 4sqrt21 X 5sqrt2 / 10sqrt7
70
2sqrt6
x^(6-3) = x^3
A = pi(r^2)

27. Nine coins are tossed simultaneously. In how many of the outcomes will the fourth coin tossed show heads?
2^9 / 2 = 256
The set of output values for a function.
The set of elements found in both A and B.
441000 = 1 10 10 10 21 * 21

28. What is the graph of f(x) shifted downward c units or spaces?
Diameter(Pi)
(b + c)
F(x) - c
9 : 25

29. What is the 'Range' of a function?
Diameter(Pi)
The set of output values for a function.
An isosceles right triangle.
1/2 times 7/3

30. Formula to find a circle'S circumference from its diameter?
2.592 kg
The third side is greater than the difference and less than the sum.
C = (pi)d
x(x - y + 1)

31. How many digits are there between the decimal point and the first even digit in the decimal equivalent of 1/[(2^8)(5^3)]
Cd
(a + b)^2
0
72

32. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
An angle which is supplementary to an interior angle.
x^(4+7) = x^11
28. n = 8 - k = 2. n! / k!(n-k)!
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.

33. What is a piecewise equation?
x= (1.2)(.8)lw
Two angles whose sum is 90.
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
11 - 13 - 17 - 19

34. Number of degrees in a triangle
180
Two angles whose sum is 180.
Sector area = (n/360) X (pi)r^2
2 & 3/7

35. What is the graph of f(x) shifted left c units or spaces?
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)
27^(-4)
F(x + c)
(base*height) / 2

36. To multiply a number by 10^x
(p + q)/5
Move the decimal point to the right x places
130pi
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

37. P and r are factors of 100. What is greater - pr or 100?
Triangles with same measure and same side lengths.
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
The objects within a set.
Indeterminable.

38. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
12! / 5!7! = 792
x^(4+7) = x^11
70
1:1:sqrt2

39. Formula of rectangle where l increases by 20% and w decreases by 20%
Lies opposite the greater angle
4725
x= (1.2)(.8)lw
1/a^6

40. Which quadrant is the upper right hand?
.0004809 X 10^11
I
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)
(a + b)^2

41. How to determine percent increase?
2(pi)r^2 + 2(pi)rh
(amount of increase/original price) x 100%
37.5%
III

42. How to find the circumference of a circle which circumscribes a square?
83.333%
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
70
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

43. Order of quadrants:
... the square of the ratios of the corresponding sides.
From northeast - counterclockwise. I - II - III - IV
Cd
28. n = 8 - k = 2. n! / k!(n-k)!

44. What is the 'domain' of a function?
...multiply by 100.
27^(-4)
G(x) = {x}
The set of input values for a function.

45. What is an exterior angle?
An angle which is supplementary to an interior angle.
55%
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
1

46. What is an arc of a circle?
A = I (1 + rt)
An arc is a portion of a circumference of a circle.
(a + b)^2
The shortest arc between points A and B on a circle'S diameter.

47. Which is greater? 200x^295 or 10x^294?
Undefined - because we can'T divide by 0.
(n-2) x 180
Relationship cannot be determined (what if x is negative?)
Indeterminable.

48. What is the area of a regular hexagon with side 6?
1.0843 X 10^11
9 & 6/7
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)
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

49. x^6 / x^3
130pi
x^(6-3) = x^3
A set with a number of elements which can be counted.
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

50. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
12.5%
Lies opposite the greater angle
Relationship cannot be determined (what if x is negative?)
An isosceles right triangle.