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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. 10^6 has how many zeroes?
83.333%
$11 -448
6
An angle which is supplementary to an interior angle.

2. 1:sqrt3:2 is the ratio of the sides of what kind of triangle?
A 30-60-90 triangle.
y = 2x^2 - 3
$3 -500 in the 9% and $2 -500 in the 7%.
Part = Percent X Whole

3. x^6 / x^3
4725
288 (8 9 4)
180 degrees
x^(6-3) = x^3

4. Simplify (a^2 + b)^2 - (a^2 - b)^2
4a^2(b)
6
27^(-4)
6

5. Ratio of ages of Anna and Emma is 3:5 and of Emma and Nicolas is 3:5. What is the ratio of Anna to Nicholas' ages?
A reflection about the origin.
Diameter(Pi)
9 : 25
6 : 1 : 2

6. If the two sides of a triangle are unequal then the longer side...
1
Lies opposite the greater angle
(a - b)(a + b)
The sum of its digits is divisible by 3.

7. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
An isosceles right triangle.
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
Yes. [i.e. f(x) = x^2 - 1

8. What is a finite set?
Undefined
Cd
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
A set with a number of elements which can be counted.

9. If an inequality is multiplied or divided by a negative number....
The direction of the inequality is reversed.
The set of input values for a function.
1.0843 X 10^11
12! / 5!7! = 792

10. A number is divisible by 6 if...
Its divisible by 2 and by 3.
1.7
31 - 37
4725

11. 413.03 x 10^(-4) =
The set of output values for a function.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
1 & 37/132
413.03 / 10^4 (move the decimal point 4 places to the left)

12. When the 'a' in a parabola is positive....
The curve opens upward and the vertex is the minimal point on the graph.
2
1/(x^y)
130pi

13. 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?
Part = Percent X Whole
C = 2(pi)r
55%
10! / (10-3)! = 720

14. What is the graph of f(x) shifted right c units or spaces?
90
Two equal sides and two equal angles.
F(x-c)
(a + b)^2

15. a^0 =
The direction of the inequality is reversed.
A set with a number of elements which can be counted.
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.

16. 6w^2 - w - 15 = 0
A central angle is an angle formed by 2 radii.
13pi / 2
A chord is a line segment joining two points on a circle.
3/2 - 5/3

17. Which is greater? 27^(-4) or 9^(-8)
From northeast - counterclockwise. I - II - III - IV
(n-2) x 180
27^(-4)
The sum of digits is divisible by 9.

18. Define a 'Term' -
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)
53 - 59
The set of output values for a function.
.0004809 X 10^11

19. 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?
III
N! / (k!)(n-k)!
Divide by 100.
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a

20. 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?
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 greatest value minus the smallest.
10! / 3!(10-3)! = 120
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.

21. Which quadrant is the upper right hand?
x^(6-3) = x^3
I
$11 -448
The second graph is less steep.

22. What are the real numbers?
2.592 kg
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)
A reflection about the axis.
Factors are few - multiples are many.

23. What is the name for a grouping of the members within a set based on a shared characteristic?
62.5%
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
A subset.
The set of elements which can be found in either A or B.

24. 0^0
180
(a - b)(a + b)
Undefined
$3 -500 in the 9% and $2 -500 in the 7%.

25. Define an 'expression'.
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
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)
Move the decimal point to the right x places
31 - 37

26. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
All numbers multiples of 1.
28. n = 8 - k = 2. n! / k!(n-k)!
Cd
The direction of the inequality is reversed.

27. What is the formula for computing simple interest?
87.5%
A = I (1 + rt)
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...
No - the input value has exactly one output.

28. What is the 'Solution' for a set of inequalities.
1
The overlapping sections.
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

29. What is an exterior angle?
37.5%
An angle which is supplementary to an interior angle.
6
Ax^2 + bx + c where a -b and c are constants and a /=0

30. What are complementary angles?
Two angles whose sum is 90.
x^(6-3) = x^3
A 30-60-90 triangle.
The set of input values for a function.

31. Can the input value of a function have more than one output value (i.e. x: y - y1)?
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)
(a + b)^2
0
No - the input value has exactly one output.

32. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
28. n = 8 - k = 2. n! / k!(n-k)!
13
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
The shortest arc between points A and B on a circle'S diameter.

33. What is the set of elements found in both A and B?
The interesection of A and B.
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
y = 2x^2 - 3
x^(4+7) = x^11

34. What is the side length of an equilateral triangle with altitude 6?
Triangles with same measure and same side lengths.
413.03 / 10^4 (move the decimal point 4 places to the left)
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...
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)

35. What is the absolute value function?
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
G(x) = {x}
72
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)

36. Nine coins are tossed simultaneously. In how many of the outcomes will the fourth coin tossed show heads?
Lies opposite the greater angle
83.333%
2^9 / 2 = 256
A set with a number of elements which can be counted.

37. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
...multiply by 100.
1
Sector area = (n/360) X (pi)r^2
2 & 3/7

38. 5/8 in percent?
90pi
62.5%
The direction of the inequality is reversed.
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

39. Formula to calculate arc length?
Arc length = (n/360) x pi(2r) where n is the number of degrees.
2^9 / 2 = 256
The longest arc between points A and B on a circle'S diameter.
The second graph is less steep.

40. 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.
IV
x^(6-3) = x^3
A = I (1 + rt)

41. 40 < all primes<50
1
F(x) - c
23 - 29
41 - 43 - 47

42. What is the graph of f(x) shifted upward c units or spaces?
F(x) + c
I
x^(6-3) = x^3
2 & 3/7

43. Legs: 3 - 4. Hypotenuse?
Lies opposite the greater angle
5
10! / (10-3)! = 720
The interesection of A and B.

44. A number is divisible by 4 is...
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
y = 2x^2 - 3
Its last two digits are divisible by 4.
Angle/360 x 2(pi)r

45. Describe the relationship between the graphs of x^2 and (1/2)x^2
The second graph is less steep.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
61 - 67
(b + c)

46. Formula of rectangle where l increases by 20% and w decreases by 20%
x= (1.2)(.8)lw
The curve opens downward and the vertex is the maximum point on the graph.
The greatest value minus the smallest.
The set of elements which can be found in either A or B.

47. If 10800 is invested at a simple interest rate of 4% - what is the value of the investment after 18 months?
$11 -448
The second graph is less steep.
A reflection about the axis.
Its last two digits are divisible by 4.

48. 20<all primes<30
4a^2(b)
5 OR -5
x^(4+7) = x^11
23 - 29

49. What is the 'Restricted domain of a function'?
441000 = 1 10 10 10 21 * 21
When the function is not defined for all real numbers -; only a subset of the real numbers.
Cd
An expression with just one term (-6x - 2a^2)

50. a^2 - b^2 =
90 degrees
(a - b)^2
C = (pi)d
(a - b)(a + b)