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. What is the formula for compounded interest?
F(x) - c
The sum of digits is divisible by 9.
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.
(a + b)^2

2. 8.84 / 5.2
The shortest arc between points A and B on a circle'S diameter.
1.7
The curve opens upward and the vertex is the minimal point on the graph.
The objects within a set.

3. (-1)^3 =
The sum of its digits is divisible by 3.
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
441000 = 1 10 10 10 21 * 21
1

4. What is the 'Range' of a series of numbers?
x= (1.2)(.8)lw
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
The greatest value minus the smallest.
(a - b)(a + b)

5. In a regular polygon with n sides - the formula for the sum of interior angles
Undefined
(n-2) x 180
The set of elements found in both A and B.
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)

6. How many digits are there between the decimal point and the first even digit in the decimal equivalent of 1/[(2^8)(5^3)]
A = I (1 + rt)
0
A tangent is a line that only touches one point on the circumference of a circle.
The set of elements found in both A and B.

7. What are the rational numbers?
23 - 29
.0004809 X 10^11
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
(n-2) x 180

8. Which quadrant is the upper right hand?
62.5%
4a^2(b)
F(x) + c
I

9. What is the ratio of the surface area of a cube with an edge of 10 to the surface area of a rectangular solid with dimensions 2 - 4 - and 6?
75:11
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
(b + c)
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

10. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
2 & 3/7
$3 -500 in the 9% and $2 -500 in the 7%.
3
A = pi(r^2)

11. What is a piecewise equation?
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
A grouping of the members within a set based on a shared characteristic.
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
C = (pi)d

12. What is a chord of a circle?
28. n = 8 - k = 2. n! / k!(n-k)!
F(x) + c
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
A chord is a line segment joining two points on a circle.

13. Simplify 9^(1/2) X 4^3 X 2^(-6)?
3
From northeast - counterclockwise. I - II - III - IV
The second graph is less steep.
C = (pi)d

14. To multiply a number by 10^x
No - the input value has exactly one output.
61 - 67
Move the decimal point to the right x places
13pi / 2

15. What is the graph of f(x) shifted downward c units or spaces?
The greatest value minus the smallest.
F(x) - c
The sum of digits is divisible by 9.
1

16. 2sqrt4 + sqrt4 =
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
A reflection about the axis.
An isosceles right triangle.
3sqrt4

17. Area of a triangle?
9 : 25
(base*height) / 2
A set with no members - denoted by a circle with a diagonal through it.
$11 -448

18. What is the maximum value for the function g(x) = (-2x^2) -1?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
1
90pi
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

19. Write 10 -843 X 10^7 in scientific notation
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
1.0843 X 10^11
1
1/2 times 7/3

20. Describe the relationship between 3x^2 and 3(x - 1)^2
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
An arc is a portion of a circumference of a circle.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
1

21. Simplify the expression (p^2 - q^2)/ -5(q - p)
(p + q)/5
1.7
7 / 1000
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).

22. For similar triangles - the ratio of their corresponding sides is 2:3. What is the ratio of their areas?
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
The set of elements found in both A and B.
A tangent is a line that only touches one point on the circumference of a circle.
1

23. 1/2 divided by 3/7 is the same as
Its divisible by 2 and by 3.
1/2 times 7/3
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
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)

24. What are the real numbers?
500
The longest arc between points A and B on a circle'S diameter.
1
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)

25. 60 < all primes <70
61 - 67
Diameter(Pi)
Sqrt 12
Relationship cannot be determined (what if x is negative?)

26. What is a subset?
1.0843 X 10^11
A grouping of the members within a set based on a shared characteristic.
No - only like radicals can be added.
Its negative reciprocal. (-b/a)

27. Which is greater? 200x^295 or 10x^294?
Angle/360 x 2(pi)r
Relationship cannot be determined (what if x is negative?)
The curve opens downward and the vertex is the maximum point on the graph.
(12/2) x (sqrt15 / sqrt5) = 6sqrt3

28. What is an exterior angle?
Two angles whose sum is 180.
An angle which is supplementary to an interior angle.
1:1:sqrt2
13pi / 2

29. What is the 'Solution' for a system of linear equations?
(base*height) / 2
The point of intersection of the systems.
Diameter(Pi)
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a

30. What number between 70 & 75 - inclusive - has the greatest number of factors?
12! / 5!7! = 792
72
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...
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.

31. sqrt 2(sqrt 6)=
x^(4+7) = x^11
Sqrt 12
12sqrt2
4096

32. 10^6 has how many zeroes?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
N! / (k!)(n-k)!
y = 2x^2 - 3
6

33. If 10800 is invested at a simple interest rate of 4% - what is the value of the investment after 18 months?
Even
The union of A and B.
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
$11 -448

34. Evaluate 3& 2/7 / 1/3
A circle centered at -2 - -2 with radius 3.
9 & 6/7
(a - b)(a + b)
The second graph is less steep.

35. Formula to calculate arc length?
2
72
Members or elements
Arc length = (n/360) x pi(2r) where n is the number of degrees.

36. 3/8 in percent?
37.5%
Even
When the function is not defined for all real numbers -; only a subset of the real numbers.
Triangles with same measure and same side lengths.

37. 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
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)
Indeterminable.
The set of elements which can be found in either A or B.
18

38. (-1)^2 =
From northeast - counterclockwise. I - II - III - IV
4725
Sector area = (n/360) X (pi)r^2
1

39. If the two sides of a triangle are unequal then the longer side...
Infinite.
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
72
Lies opposite the greater angle

40. What is the graph of f(x) shifted right c units or spaces?
(a - b)(a + b)
1
F(x-c)
x^(4+7) = x^11

41. Evaluate (4^3)^2
An arc is a portion of a circumference of a circle.
y = 2x^2 - 3
The interesection of A and B.
4096

42. What is the set of elements which can be found in either A or B?
The union of A and B.
Angle/360 x (pi)r^2
87.5%
4725

43. What is the sum of the angles of a triangle?
180 degrees
Pi is the ratio of a circle'S circumference to its diameter.
The set of elements which can be found in either A or B.
A circle centered at -2 - -2 with radius 3.

44. 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?
16.6666%
Arc length = (n/360) x pi(2r) where n is the number of degrees.
N! / (k!)(n-k)!
No - only like radicals can be added.

45. Max and Min lengths for a side of a triangle?
The third side is greater than the difference and less than the sum.
13pi / 2
Area of the base X height = (pi)hr^2
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)

46. 10<all primes<20
11 - 13 - 17 - 19
2sqrt6
4a^2(b)
An infinite set.

47. There are 10 finalists for the school spelling bee. A first - second - and third place trophy will be awarded. How many different people can get the three prizes?
12! / 5!7! = 792
Its negative reciprocal. (-b/a)
x(x - y + 1)
10! / 3!(10-3)! = 120

48. Can you simplify sqrt72?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
The empty set - denoted by a circle with a diagonal through it.
$3 -500 in the 9% and $2 -500 in the 7%.
True

49. Simplify (a^2 + b)^2 - (a^2 - b)^2
4a^2(b)
The third side is greater than the difference and less than the sum.
48
90

50. Which is greater? 27^(-4) or 9^(-8)
27^(-4)
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...
1.7
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.