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. Formula for the area of a circle?
A = pi(r^2)
(amount of decrease/original price) x 100%
500
Two equal sides and two equal angles.

2. Simplify the expression [(b^2 - c^2) / (b - c)]
An expression with just one term (-6x - 2a^2)
(b + c)
An isosceles right triangle.
2^9 / 2 = 256

3. a^2 + 2ab + b^2
IV
From northeast - counterclockwise. I - II - III - IV
(a + b)^2
1 & 37/132

4. What is the 'Restricted domain of a function'?
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
Its negative reciprocal. (-b/a)
1:sqrt3:2
When the function is not defined for all real numbers -; only a subset of the real numbers.

5. What is the 'Solution' for a system of linear equations?
Yes. [i.e. f(x) = x^2 - 1
The point of intersection of the systems.
1
An expression with just one term (-6x - 2a^2)

6. What is an exterior angle?
An angle which is supplementary to an interior angle.
From northeast - counterclockwise. I - II - III - IV
12! / 5!7! = 792
Part = Percent X Whole

7. 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?
I
All numbers multiples of 1.
Pi is the ratio of a circle'S circumference to its diameter.
$3 -500 in the 9% and $2 -500 in the 7%.

8. What are the roots of the quadrinomial x^2 + 2x + 1?
4725
N! / (k!)(n-k)!
G(x) = {x}
The two xes after factoring.

9. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
Move the decimal point to the right x places
F(x-c)
The empty set - denoted by a circle with a diagonal through it.
Cd

10. a^2 - b^2
31 - 37
I
(a - b)(a + b)
3/2 - 5/3

11. For what values should the domain be restricted for the function f(x) = sqrt(x + 8)
8
12sqrt2
20.5
1.7

12. For similar triangles - the ratio of their corresponding sides is 2:3. What is the ratio of their areas?
A set with a number of elements which can be counted.
A = I (1 + rt)
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
13

13. A triangle is inscribed in a semi circle with legs 5 and 12. What is the circumfermence of the semicircle?
13pi / 2
31 - 37
52
Sqrt 12

14. Can you subtract 3sqrt4 from sqrt4?
Yes - like radicals can be added/subtracted.
9 & 6/7
C = 2(pi)r
The overlapping sections.

15. How to find the diagonal of a rectangular solid?
4725
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
41 - 43 - 47
10! / 3!(10-3)! = 120

16. 3/8 in percent?
37.5%
Yes - like radicals can be added/subtracted.
Members or elements
$11 -448

17. 25^(1/2) or sqrt. 25 =
5 OR -5
10! / 3!(10-3)! = 120
Undefined - because we can'T divide by 0.
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

18. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
The curve opens downward and the vertex is the maximum point on the graph.
Cd
4:5

19. 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?
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.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
2.592 kg

20. How to determine percent decrease?
(amount of decrease/original price) x 100%
C = 2(pi)r
Part = Percent X Whole
75:11

21. If Madagascar'S exports totaled 1.3 billion in 2009 - and 4% came from China - what was the value in millions of the country'S exports to China?
16.6666%
52
Area of the base X height = (pi)hr^2
1

22. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
Members or elements
12.5%
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
4a^2(b)

23. (a^-1)/a^5
A reflection about the axis.
1/a^6
67 - 71 - 73
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.

24. What is a finite set?
A set with a number of elements which can be counted.
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.
2.592 kg
5

25. Which quandrant is the lower right hand?
(base*height) / 2
C = (pi)d
3
IV

26. (x^2)^4
0
Pi is the ratio of a circle'S circumference to its diameter.
x^(2(4)) =x^8 = (x^4)^2
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.

27. Whats the difference between factors and multiples?
Indeterminable.
5 OR -5
The set of output values for a function.
Factors are few - multiples are many.

28. 60 < all primes <70
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 overlapping sections.
61 - 67
5

29. When the 'a' in the parabola is negative...
1
The steeper the slope.
The curve opens downward and the vertex is the maximum point on the graph.
288 (8 9 4)

30. Is 0 even or odd?
(base*height) / 2
10
Even
Two equal sides and two equal angles.

31. What is the measure of an exterior angle of a regular pentagon?
2.592 kg
The second graph is less steep.
31 - 37
72

32. 2sqrt4 + sqrt4 =
3sqrt4
Even
A chord is a line segment joining two points on a circle.
I

33. What is the surface area of a cylinder with radius 5 and height 8?
Divide by 100.
288 (8 9 4)
130pi
90 degrees

34. 4.809 X 10^7 =
67 - 71 - 73
20.5
.0004809 X 10^11
(a - b)^2

35. A company places a 6-symbol code on each product. The code consists of the letter T - followed by 3 numerical digits - and then 2 consonants (Y is a conson). How many codes are possible?
Two angles whose sum is 180.
The sum of digits is divisible by 9.
441000 = 1 10 10 10 21 * 21
Its last two digits are divisible by 4.

36. 70 < all primes< 80
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
The second graph is less steep.
II
71 - 73 - 79

37. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
Area of the base X height = (pi)hr^2
70
The empty set - denoted by a circle with a diagonal through it.
The interesection of A and B.

38. x^(-y)=
(b + c)
The overlapping sections.
1/(x^y)
3/2 - 5/3

39. What is a set with no members called?
4725
The empty set - denoted by a circle with a diagonal through it.
13
Indeterminable.

40. Can the output value of a function have more than one input value?
The point of intersection of the systems.
Yes. [i.e. f(x) = x^2 - 1
Sector area = (n/360) X (pi)r^2
.0004809 X 10^11

41. 6w^2 - w - 15 = 0
$3 -500 in the 9% and $2 -500 in the 7%.
3/2 - 5/3
Its negative reciprocal. (-b/a)
A 30-60-90 triangle.

42. x^4 + x^7 =
(n-2) x 180
x^(4+7) = x^11
Even
The point of intersection of the systems.

43. If the two sides of a triangle are unequal then the longer side...
A chord is a line segment joining two points on a circle.
6 : 1 : 2
Lies opposite the greater angle
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

44. 5/8 in percent?
F(x + c)
288 (8 9 4)
6
62.5%

45. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
1 & 37/132
28. n = 8 - k = 2. n! / k!(n-k)!
y = 2x^2 - 3

46. (12sqrt15) / (2sqrt5) =
.0004809 X 10^11
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 second graph is less steep.
(12/2) x (sqrt15 / sqrt5) = 6sqrt3

47. What is the 'Range' of a series of numbers?
(b + c)
The greatest value minus the smallest.
F(x + c)
The set of elements found in both A and B.

48. Which is greater? 27^(-4) or 9^(-8)
A central angle is an angle formed by 2 radii.
27^(-4)
A set with a number of elements which can be counted.
13

49. What is the absolute value function?
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
441000 = 1 10 10 10 21 * 21
G(x) = {x}
2.592 kg

50. What transformation occurs if point C is reflected over the x-axis and then the y-axis?
A reflection about the axis.
The sum of its digits is divisible by 3.
27^(-4)
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.