Test your basic knowledge |

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. The number of degrees in the largest angle of a triangle inscribed in a circle - in which the diameter of the circle is one side of the triangle.
y = 2x^2 - 3
Its divisible by 2 and by 3.
IV
90 degrees

2. (a^-1)/a^5
52
1/a^6
61 - 67
Lies opposite the greater angle

3. What is the coefficient of the x^2 term in the product of (x + 1)(x + 2)(x -1)?
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.
2
(a - b)(a + b)
.0004809 X 10^11

4. x^4 + x^7 =
Members or elements
IV
x^(4+7) = x^11
G(x) = {x}

5. x^2 = 9. What is the value of x?
A reflection about the origin.
3/2 - 5/3
67 - 71 - 73
3 - -3

6. If the 80th percentile of the measurements is 72degrees - about how many measurments are between 69 degrees and 72 degrees? Round your answer to the nearest tenth
Triangles with same measure and same side lengths.
Members or elements
18
1

7. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
The second graph is less steep.
The sum of its digits is divisible by 3.
2 & 3/7
F(x + c)

8. What is the formula for computing simple interest?
A chord is a line segment joining two points on a circle.
A = I (1 + rt)
I
(a - b)(a + b)

9. 6w^2 - w - 15 = 0
3/2 - 5/3
x^(6-3) = x^3
(n-2) x 180
A 30-60-90 triangle.

10. Whats the difference between factors and multiples?
1:sqrt3:2
Factors are few - multiples are many.
1
6

11. a^2 - 2ab + b^2
(a - b)^2
1:sqrt3:2
Its last two digits are divisible by 4.
7 / 1000

12. What percent of 40 is 22?
13pi / 2
Sqrt 12
55%
From northeast - counterclockwise. I - II - III - IV

13. Can you simplify sqrt72?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
A circle centered on the origin with radius 8.
Its last two digits are divisible by 4.
1/2 times 7/3

14. How many 3-digit positive integers are even and do not contain the digit 4?
A circle centered on the origin with radius 8.
$11 -448
12! / 5!7! = 792
288 (8 9 4)

15. P and r are factors of 100. What is greater - pr or 100?
When the function is not defined for all real numbers -; only a subset of the real numbers.
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
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...
Indeterminable.

16. What is the graph of f(x) shifted left c units or spaces?
8
A central angle is an angle formed by 2 radii.
180 degrees
F(x + c)

17. Legs 6 - 8. Hypotenuse?
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
10
The empty set - denoted by a circle with a diagonal through it.
1/a^6

18. What is the formula for compounded interest?
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.
4a^2(b)
1
The shortest arc between points A and B on a circle'S diameter.

19. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
A circle centered at -2 - -2 with radius 3.
The two xes after factoring.
28. n = 8 - k = 2. n! / k!(n-k)!
II

20. 10^6 has how many zeroes?
.0004809 X 10^11
6
1
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

21. 8.84 / 5.2
1.7
C = 2(pi)r
F(x) - c
No - the input value has exactly one output.

22. Nine coins are tossed simultaneously. In how many of the outcomes will the fourth coin tossed show heads?
72
18
2^9 / 2 = 256
The empty set - denoted by a circle with a diagonal through it.

23. A number is divisible by 3 if ...
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
Members or elements
The sum of its digits is divisible by 3.

24. 1/8 in percent?
12.5%
(a - b)(a + b)
III
F(x-c)

25. Is 0 even or odd?
A tangent is a line that only touches one point on the circumference of a circle.
No - the input value has exactly one output.
Even
90pi

26. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
Sector area = (n/360) X (pi)r^2
Cd
The curve opens downward and the vertex is the maximum point on the graph.
1/(x^y)

27. 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.
Area of the base X height = (pi)hr^2
Yes. [i.e. f(x) = x^2 - 1
1

28. 5x^2 - 35x -55 = 0
The shortest arc between points A and B on a circle'S diameter.
(amount of decrease/original price) x 100%
3
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]

29. a^2 - b^2
The sum of its digits is divisible by 3.
Undefined
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
(a - b)(a + b)

30. What does the graph (x+2)^2 + (y+2)^2 = 9 look like?
12.5%
Two angles whose sum is 90.
Sqrt 12
A circle centered at -2 - -2 with radius 3.

31. 70 < all primes< 80
Pi is the ratio of a circle'S circumference to its diameter.
A subset.
71 - 73 - 79
All numbers multiples of 1.

32. Which quadrant is the upper right hand?
48
(amount of decrease/original price) x 100%
I
A reflection about the axis.

33. 20<all primes<30
3 - -3
288 (8 9 4)
23 - 29
6

34. Describe the relationship between the graphs of x^2 and (1/2)x^2
The second graph is less steep.
An angle which is supplementary to an interior angle.
1
Angle/360 x (pi)r^2

35. Formula to calculate arc length?
4725
Even
(a - b)^2
Arc length = (n/360) x pi(2r) where n is the number of degrees.

36. What are the integers?
3
All numbers multiples of 1.
I
A = pi(r^2)

37. Surface area for a cylinder?
The third side is greater than the difference and less than the sum.
F(x) - c
2(pi)r^2 + 2(pi)rh
x^(6-3) = x^3

38. A number is divisible by 9 if...
G(x) = {x}
Part = Percent X Whole
C = (pi)d
The sum of digits is divisible by 9.

39. Evaluate 3& 2/7 / 1/3
Sqrt 12
37.5%
9 & 6/7
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)

40. sqrt 2(sqrt 6)=
A set with no members - denoted by a circle with a diagonal through it.
9 & 6/7
1.0843 X 10^11
Sqrt 12

41. How to determine percent decrease?
1
Divide by 100.
A = pi(r^2)
(amount of decrease/original price) x 100%

42. How to find the diagonal of a rectangular solid?
7 / 1000
...multiply by 100.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
A set with a number of elements which can be counted.

43. What is the 'Solution' for a set of inequalities.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
The overlapping sections.
11 - 13 - 17 - 19
The point of intersection of the systems.

44. What is the side length of an equilateral triangle with altitude 6?
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...
F(x + c)
An isosceles right triangle.
$11 -448

45. What is a chord of a circle?
6 : 1 : 2
A chord is a line segment joining two points on a circle.
A set with no members - denoted by a circle with a diagonal through it.
The set of input values for a function.

46. How to find the circumference of a circle which circumscribes a square?
The point of intersection of the systems.
Even
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
III

47. If an inequality is multiplied or divided by a negative number....
A = I (1 + rt)
A circle centered at -2 - -2 with radius 3.
Arc length = (n/360) x pi(2r) where n is the number of degrees.
The direction of the inequality is reversed.

48. How many multiples does a given number have?
No - the input value has exactly one output.
(amount of decrease/original price) x 100%
Infinite.
A set with a number of elements which can be counted.

49. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
A set with no members - denoted by a circle with a diagonal through it.
(n-2) x 180
1

50. 4.809 X 10^7 =
x^(4+7) = x^11
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
.0004809 X 10^11
x= (1.2)(.8)lw