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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. Nine coins are tossed simultaneously. In how many of the outcomes will the fourth coin tossed show heads?
Triangles with same measure and same side lengths.
(a - b)(a + b)
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
2^9 / 2 = 256

2. What is a major arc?

3. What are the irrational numbers?

4. (-1)^3 =
1
F(x) - c
(b + c)
180 degrees

5. How many sides does a hexagon have?
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.
6 : 1 : 2
6
(amount of increase/original price) x 100%

6. What is the 'Range' of a function?
The set of output values for a function.
2(pi)r^2 + 2(pi)rh
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)
(a - b)(a + b)

7. For similar triangles - the ratio of their corresponding sides is 2:3. What is the ratio of their areas?
Two angles whose sum is 90.
9 & 6/7
1/a^6
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.

8. What is the third quartile of the following data set: 44 - 58 - 63 - 63 - 68 - 70 - 82
The overlapping sections.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
70
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).

9. 5/6 in percent?
...multiply by 100.
An arc is a portion of a circumference of a circle.
83.333%
The second graph is less steep.

10. To multiply a number by 10^x
A 30-60-90 triangle.
A reflection about the origin.
x^(6-3) = x^3
Move the decimal point to the right x places

11. 5/8 in percent?
62.5%
2.592 kg
10
Infinite.

12. (6sqrt3) x (2sqrt5) =
4:5
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
31 - 37
Ax^2 + bx + c where a -b and c are constants and a /=0

13. What are the rational numbers?
2 & 3/7
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
A circle centered on the origin with radius 8.

14. When does a function automatically have a restricted domain (2)?
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
1/2 times 7/3
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
F(x) - c

15. 2sqrt4 + sqrt4 =
y = 2x^2 - 3
3sqrt4
The set of input values for a function.
Sector area = (n/360) X (pi)r^2

16. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
Infinite.
28. n = 8 - k = 2. n! / k!(n-k)!
Cd
0

17. What is the surface area of a cylinder with radius 5 and height 8?
8
130pi
Sector area = (n/360) X (pi)r^2
x(x - y + 1)

18. What is a set with no members called?
0
The curve opens downward and the vertex is the maximum point on the graph.
The empty set - denoted by a circle with a diagonal through it.
Angle/360 x 2(pi)r

19. 70 < all primes< 80
71 - 73 - 79
G(x) = {x}
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
Two angles whose sum is 90.

20. The perimeter of a square is 48 inches. The length of its diagonal is:
Even
12sqrt2
Angle/360 x (pi)r^2
The curve opens upward and the vertex is the minimal point on the graph.

21. (-1)^2 =
The set of output values for a function.
A 30-60-90 triangle.
1
53 - 59

22. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
When the function is not defined for all real numbers -; only a subset of the real numbers.
(a + b)^2
An isosceles right triangle.
N! / (k!)(n-k)!

23. a^0 =
1
The longest arc between points A and B on a circle'S diameter.
.0004809 X 10^11
(amount of increase/original price) x 100%

24. What is a parabola?
Ax^2 + bx + c where a -b and c are constants and a /=0
Undefined - because we can'T divide by 0.
I
The union of A and B.

25. When the 'a' in the parabola is negative...
Angle/360 x 2(pi)r
The curve opens downward and the vertex is the maximum point on the graph.
3
87.5%

26. Which quadrant is the upper left hand?
67 - 71 - 73
C = (pi)d
II
8

27. 3/8 in percent?
(a + b)^2
x^(2(4)) =x^8 = (x^4)^2
37.5%
Factors are few - multiples are many.

28. Evaluate 4/11 + 11/12
$3 -500 in the 9% and $2 -500 in the 7%.
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)
1 & 37/132
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)

29. What is a subset?
A grouping of the members within a set based on a shared characteristic.
F(x) - c
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
x= (1.2)(.8)lw

30. What is the name for a grouping of the members within a set based on a shared characteristic?
1.7
A subset.
Its negative reciprocal. (-b/a)
Infinite.

31. What is the 'domain' of a function?
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.
The set of input values for a function.
An arc is a portion of a circumference of a circle.
1

32. 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)]?
130pi
F(x-c)
3
True

33. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
x^(2(4)) =x^8 = (x^4)^2
4:5
$3 -500 in the 9% and $2 -500 in the 7%.
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

34. 10<all primes<20
(amount of increase/original price) x 100%
.0004809 X 10^11
11 - 13 - 17 - 19
Sector area = (n/360) X (pi)r^2

35. In a triangle inscribed inside a circle - where the diameter is one side of the triangle - which angle is largest?
y = 2x^2 - 3
Ax^2 + bx + c where a -b and c are constants and a /=0
72
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.

36. What is the name of set with a number of elements which cannot be counted?
23 - 29
The two xes after factoring.
An infinite set.
An arc is a portion of a circumference of a circle.

37. Whats the difference between factors and multiples?
Factors are few - multiples are many.
x^(6-3) = x^3
4a^2(b)
The union of A and B.

38. Find the surface area of a cylinder with radius 3 and height 12.
1
90pi
1
1

39. How to determine percent decrease?
x^(6-3) = x^3
1
(amount of decrease/original price) x 100%
20.5

40. 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?
An infinite set.
Cd
10! / 3!(10-3)! = 120
F(x + c)

41. Simplify (a^2 + b)^2 - (a^2 - b)^2
3/2 - 5/3
4a^2(b)
The curve opens upward and the vertex is the minimal point on the graph.
Even

42. What is the set of elements which can be found in either A or B?
$3 -500 in the 9% and $2 -500 in the 7%.
(a - b)(a + b)
The sum of digits is divisible by 9.
The union of A and B.

43. Area of a triangle?
23 - 29
2.592 kg
(base*height) / 2
The interesection of A and B.

44. A triangle is inscribed in a semi circle with legs 5 and 12. What is the circumfermence of the semicircle?
9 & 6/7
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
Its last two digits are divisible by 4.
13pi / 2

45. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
87.5%
The shortest arc between points A and B on a circle'S diameter.
4725
28. n = 8 - k = 2. n! / k!(n-k)!

46. If an inequality is multiplied or divided by a negative number....
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
The direction of the inequality is reversed.
C = (pi)d
Sector area = (n/360) X (pi)r^2

47. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
x^(4+7) = x^11
2 & 3/7
A reflection about the origin.

48. 50 < all primes< 60
A circle centered at -2 - -2 with radius 3.
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
(n-2) x 180
53 - 59

49. 5 bakeries sell an average of 300 muffins per bakery per day. If 2 stop making muffins but the total muffins sold stays the same - what is the average of muffins per bakery sold among the remaining?
75:11
500
10! / 3!(10-3)! = 120
Two angles whose sum is 180.

50. Legs: 3 - 4. Hypotenuse?
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
5
y = 2x^2 - 3
4:5