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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. Find the surface area of a cylinder with radius 3 and height 12.
90pi
9 & 6/7
A central angle is an angle formed by 2 radii.
61 - 67

2. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
The longest arc between points A and B on a circle'S diameter.
No - only like radicals can be added.
53 - 59
1

3. What is the maximum value for the function g(x) = (-2x^2) -1?
27^(-4)
From northeast - counterclockwise. I - II - III - IV
1
The set of elements which can be found in either A or B.

4. Legs 6 - 8. Hypotenuse?
Sqrt 12
2sqrt6
x^(4+7) = x^11
10

5. In a regular polygon with n sides - the formula for the sum of interior angles
(n-2) x 180
3 - -3
Infinite.
Its last two digits are divisible by 4.

6. Define a 'Term' -
41 - 43 - 47
(a + b)^2
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)

7. A number is divisible by 6 if...
The empty set - denoted by a circle with a diagonal through it.
Lies opposite the greater angle
Its divisible by 2 and by 3.
Pi is the ratio of a circle'S circumference to its diameter.

8. What is a central angle?
The greatest value minus the smallest.
The objects within a set.
A central angle is an angle formed by 2 radii.
2 & 3/7

9. 7/8 in percent?
87.5%
Infinite.
(p + q)/5
61 - 67

10. What are congruent triangles?
II
Infinite.
9 & 6/7
Triangles with same measure and same side lengths.

11. What are the integers?
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...
All numbers multiples of 1.
2.592 kg
6

12. 2sqrt4 + sqrt4 =
1
3sqrt4
10! / (10-3)! = 720
0

13. 5/8 in percent?
62.5%
Divide by 100.
12! / 5!7! = 792
27^(-4)

14. What is the set of elements which can be found in either A or B?
62.5%
II
The union of A and B.
16.6666%

15. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
(b + c)
A set with a number of elements which can be counted.
70
3/2 - 5/3

16. How to find the area of a sector?
Angle/360 x (pi)r^2
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
A tangent is a line that only touches one point on the circumference of a circle.
7 / 1000

17. 5/6 in percent?
1/a^6
83.333%
62.5%
A circle centered at -2 - -2 with radius 3.

18. What is the graph of f(x) shifted downward c units or spaces?
10! / (10-3)! = 720
F(x) - c
Members or elements
The two xes after factoring.

19. What is the side length of an equilateral triangle with altitude 6?
72
2.592 kg
The overlapping sections.
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...

20. What percent of 40 is 22?
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
55%
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
The greatest value minus the smallest.

21. sqrt 2(sqrt 6)=
1.7
Sqrt 12
F(x + c)
The union of A and B.

22. What number between 70 & 75 - inclusive - has the greatest number of factors?
3
Sqrt 12
True
72

23. 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?
The union of A and B.
$3 -500 in the 9% and $2 -500 in the 7%.
8
Yes - like radicals can be added/subtracted.

24. a^2 - b^2 =
(a - b)(a + b)
Pi is the ratio of a circle'S circumference to its diameter.
Even
67 - 71 - 73

25. Order of quadrants:
The two xes after factoring.
1
4.25 - 6 - 22
From northeast - counterclockwise. I - II - III - IV

26. What is the 'Solution' for a set of inequalities.
(a - b)(a + b)
The overlapping sections.
23 - 29
(p + q)/5

27. The ratio of the areas of two similar polygons is ...
2
x(x - y + 1)
... the square of the ratios of the corresponding sides.
1

28. Formula to find a circle'S circumference from its radius?
C = 2(pi)r
4:5
(amount of decrease/original price) x 100%
$11 -448

29. What is the 'Restricted domain of a function'?
500
When the function is not defined for all real numbers -; only a subset of the real numbers.
The shortest arc between points A and B on a circle'S diameter.
1

30. Define a 'monomial'
Sqrt 12
6 : 1 : 2
The second graph is less steep.
An expression with just one term (-6x - 2a^2)

31. a^0 =
1:1:sqrt2
Its negative reciprocal. (-b/a)
Triangles with same measure and same side lengths.
1

32. The perimeter of a square is 48 inches. The length of its diagonal is:
(b + c)
12sqrt2
55%
Undefined

33. What are the rational numbers?
C = 2(pi)r
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
1

34. How to determine percent increase?
(a + b)^2
(amount of increase/original price) x 100%
62.5%
(amount of decrease/original price) x 100%

35. a^2 + 2ab + b^2
A reflection about the axis.
4:5
$11 -448
(a + b)^2

36. What are the smallest three prime numbers greater than 65?
67 - 71 - 73
4725
The sum of digits is divisible by 9.
Sector area = (n/360) X (pi)r^2

37. 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?
A central angle is an angle formed by 2 radii.
10! / (10-3)! = 720
1
41 - 43 - 47

38. Simplify 4sqrt21 X 5sqrt2 / 10sqrt7
(base*height) / 2
72
2sqrt6
A set with a number of elements which can be counted.

39. What does the graph x^2 + y^2 = 64 look like?
31 - 37
83.333%
A circle centered on the origin with radius 8.
N! / (n-k)!

40. x^2 = 9. What is the value of x?
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 central angle is an angle formed by 2 radii.
4725
3 - -3

41. 30< all primes<40
2 & 3/7
23 - 29
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
31 - 37

42. Simplify the expression (p^2 - q^2)/ -5(q - p)
The curve opens downward and the vertex is the maximum point on the graph.
Relationship cannot be determined (what if x is negative?)
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
(p + q)/5

43. 0^0
Undefined
70
An expression with just one term (-6x - 2a^2)
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

44. 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)]?
True
A circle centered on the origin with radius 8.
130pi
72

45. (6sqrt3) x (2sqrt5) =
1
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
3/2 - 5/3
500

46. What is the ratio of the sides of a 30-60-90 triangle?
1
Undefined
16.6666%
1:sqrt3:2

47. What is an exterior angle?
The third side is greater than the difference and less than the sum.
An angle which is supplementary to an interior angle.
4a^2(b)
4.25 - 6 - 22

48. x^4 + x^7 =
Diameter(Pi)
87.5%
x^(4+7) = x^11
An isosceles right triangle.

49. Reduce: 4.8 : 0.8 : 1.6
1/a^6
6 : 1 : 2
An angle which is supplementary to an interior angle.
18

50. What is the name of set with a number of elements which cannot be counted?
An infinite set.
413.03 / 10^4 (move the decimal point 4 places to the left)
y = (x + 5)/2
28. n = 8 - k = 2. n! / k!(n-k)!