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. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
130pi
41 - 43 - 47
An isosceles right triangle.
6

2. 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)]?
Two angles whose sum is 90.
... the square of the ratios of the corresponding sides.
Part = Percent X Whole
True

3. What are congruent triangles?
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
C = (pi)d
Triangles with same measure and same side lengths.
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)

4. 50 < all primes< 60
The empty set - denoted by a circle with a diagonal through it.
53 - 59
An isosceles right triangle.
C = (pi)d

5. What is the intersection of A and B?
3sqrt4
1
The set of elements found in both A and B.
75:11

6. What is the name of set with a number of elements which cannot be counted?
Indeterminable.
Arc length = (n/360) x pi(2r) where n is the number of degrees.
An infinite set.
The set of input values for a function.

7. From a box of 12 candles - you are to remove 5. How many different sets of 5 candles could you remove?
2
2.592 kg
1.7
12! / 5!7! = 792

8. What is a parabola?
12! / 5!7! = 792
Diameter(Pi)
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...
Ax^2 + bx + c where a -b and c are constants and a /=0

9. 5/8 in percent?
413.03 / 10^4 (move the decimal point 4 places to the left)
62.5%
48
F(x) + c

10. Volume for a cylinder?
288 (8 9 4)
Area of the base X height = (pi)hr^2
12! / 5!7! = 792
A = I (1 + rt)

11. 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?
A circle centered on the origin with radius 8.
4:5
A grouping of the members within a set based on a shared characteristic.
N! / (k!)(n-k)!

12. a^2 + 2ab + b^2
1
An expression with just one term (-6x - 2a^2)
(a + b)^2
16.6666%

13. Describe the relationship between the graphs of x^2 and (1/2)x^2
(amount of decrease/original price) x 100%
All numbers multiples of 1.
The third side is greater than the difference and less than the sum.
The second graph is less steep.

14. What is a set with no members called?
4a^2(b)
The empty set - denoted by a circle with a diagonal through it.
A = I (1 + rt)
4096

15. 1:sqrt3:2 is the ratio of the sides of what kind of triangle?
A = pi(r^2)
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
A 30-60-90 triangle.
A reflection about the axis.

16. a^0 =
Undefined
1
90 degrees
53 - 59

17. What is a tangent?
$11 -448
4.25 - 6 - 22
A tangent is a line that only touches one point on the circumference of a circle.
.0004809 X 10^11

18. Surface area for a cylinder?
Pi is the ratio of a circle'S circumference to its diameter.
2(pi)r^2 + 2(pi)rh
6
F(x) - c

19. A number is divisible by 3 if ...
The empty set - denoted by a circle with a diagonal through it.
7 / 1000
x^(2(4)) =x^8 = (x^4)^2
The sum of its digits is divisible by 3.

20. What is a finite set?
23 - 29
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.
C = 2(pi)r
A set with a number of elements which can be counted.

21. Simplify the expression (p^2 - q^2)/ -5(q - p)
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)
(p + q)/5
From northeast - counterclockwise. I - II - III - IV
2 & 3/7

22. 10<all primes<20
The empty set - denoted by a circle with a diagonal through it.
2.592 kg
y = (x + 5)/2
11 - 13 - 17 - 19

23. Can you simplify sqrt72?
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
x= (1.2)(.8)lw
71 - 73 - 79
83.333%

24. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
A tangent is a line that only touches one point on the circumference of a circle.
(p + q)/5
(a - b)(a + b)
90

25. Describe the relationship between 3x^2 and 3(x - 1)^2
72
5
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
(a + b)^2

26. What are complementary angles?
3
The curve opens upward and the vertex is the minimal point on the graph.
Two angles whose sum is 90.
500

27. What are the integers?
4725
61 - 67
N! / (k!)(n-k)!
All numbers multiples of 1.

28. 60 < all primes <70
3 - -3
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
61 - 67
500

29. 2sqrt4 + sqrt4 =
28. n = 8 - k = 2. n! / k!(n-k)!
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
3sqrt4
The set of output values for a function.

30. What is the graph of f(x) shifted downward c units or spaces?
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.
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)
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
F(x) - c

31. Number of degrees in a triangle
Yes. [i.e. f(x) = x^2 - 1
9 & 6/7
180
A chord is a line segment joining two points on a circle.

32. What is the 'Range' of a function?
The set of output values for a function.
An expression with just one term (-6x - 2a^2)
1
12.5%

33. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
4.25 - 6 - 22
A set with no members - denoted by a circle with a diagonal through it.
An infinite set.
2 & 3/7

34. 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...
31 - 37
27^(-4)
Move the decimal point to the right x places

35. a^2 - b^2 =
(a - b)(a + b)
7 / 1000
67 - 71 - 73
The direction of the inequality is reversed.

36. What is the formula for compounded interest?
1.0843 X 10^11
No - the input value has exactly one output.
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.
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...

37. Formula to find a circle'S circumference from its diameter?
Yes - like radicals can be added/subtracted.
C = (pi)d
61 - 67
A reflection about the axis.

38. Legs 5 - 12. Hypotenuse?
90pi
Triangles with same measure and same side lengths.
2 & 3/7
13

39. sqrt 2(sqrt 6)=
x(x - y + 1)
Sqrt 12
3
10! / 3!(10-3)! = 120

40. What is the graph of f(x) shifted upward c units or spaces?
48
F(x) + c
9 & 6/7
2.592 kg

41. 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.
12.5%
11 - 13 - 17 - 19
Diameter(Pi)

42. What are the real numbers?
12sqrt2
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)
The curve opens downward and the vertex is the maximum point on the graph.
The set of input values for a function.

43. 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?
Infinite.
A central angle is an angle formed by 2 radii.
10! / (10-3)! = 720
x^(2(4)) =x^8 = (x^4)^2

44. What is the 'domain' of a function?
0
41 - 43 - 47
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)
The set of input values for a function.

45. How many multiples does a given number have?
10
13
Infinite.
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]

46. What is the graph of f(x) shifted left c units or spaces?
4a^2(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)
F(x + c)
(a - b)^2

47. In a regular polygon with n sides - the formula for the sum of interior angles
28. n = 8 - k = 2. n! / k!(n-k)!
(n-2) x 180
12sqrt2
$11 -448

48. Formula for the area of a circle?
3/2 - 5/3
A = pi(r^2)
12! / 5!7! = 792
x(x - y + 1)

49. 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?
180
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 set with no members - denoted by a circle with a diagonal through it.
48

50. Legs 6 - 8. Hypotenuse?
67 - 71 - 73
23 - 29
y = (x + 5)/2
10