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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. If 10800 is invested at a simple interest rate of 4% - what is the value of the investment after 18 months?
$11 -448
The steeper the slope.
Members or elements
... the square of the ratios of the corresponding sides.

2. Which is greater? 27^(-4) or 9^(-8)
8
27^(-4)
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
9 : 25

3. What is a central angle?
3 - -3
Angle/360 x 2(pi)r
A central angle is an angle formed by 2 radii.
0

4. (12sqrt15) / (2sqrt5) =
The curve opens downward and the vertex is the maximum point on the graph.
(12/2) x (sqrt15 / sqrt5) = 6sqrt3
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
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)

5. How to determine percent increase?
Cd
(amount of increase/original price) x 100%
F(x) - c
500

6. What is the 'Restricted domain of a function'?
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 set of elements which can be found in either A or B.
No - only like radicals can be added.
When the function is not defined for all real numbers -; only a subset of the real numbers.

7. Order of quadrants:
x^(6-3) = x^3
9 : 25
From northeast - counterclockwise. I - II - III - IV
53 - 59

8. When the 'a' in a parabola is positive....
When the function is not defined for all real numbers -; only a subset of the real numbers.
9 : 25
The curve opens upward and the vertex is the minimal point on the graph.
Indeterminable.

9. 0^0
Ax^2 + bx + c where a -b and c are constants and a /=0
Undefined
20.5
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

10. What is a minor arc?

11. Formula for the area of a sector of a circle?
A subset.
Sector area = (n/360) X (pi)r^2
1
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.

12. Simplify (a^2 + b)^2 - (a^2 - b)^2
A subset.
Its divisible by 2 and by 3.
4a^2(b)
F(x + c)

13. What is the 'Solution' for a set of inequalities.
71 - 73 - 79
The overlapping sections.
(a - b)(a + b)
12.5%

14. If an inequality is multiplied or divided by a negative number....
Its negative reciprocal. (-b/a)
The curve opens upward and the vertex is the minimal point on the graph.
The direction of the inequality is reversed.
Lies opposite the greater angle

15. What is the order of operations?
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.
A 30-60-90 triangle.
(amount of increase/original price) x 100%

16. What is a tangent?
90pi
A tangent is a line that only touches one point on the circumference of a circle.
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
Undefined - because we can'T divide by 0.

17. 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?
9 : 25
IV
It is a function defined by more than one equation - where each equation applies to a different part of the domain of the function.
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)

18. To multiply a number by 10^x
The set of output values for a function.
18
The third side is greater than the difference and less than the sum.
Move the decimal point to the right x places

19. Simplify 4sqrt21 X 5sqrt2 / 10sqrt7
2sqrt6
(b + c)
75:11
Cd

20. A triangle is inscribed in a semi circle with legs 5 and 12. What is the circumfermence of the semicircle?
13pi / 2
A set with no members - denoted by a circle with a diagonal through it.
75:11
The third side is greater than the difference and less than the sum.

21. Simplify 9^(1/2) X 4^3 X 2^(-6)?
2(pi)r^2 + 2(pi)rh
3
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
The direction of the inequality is reversed.

22. What is the graph of f(x) shifted downward c units or spaces?
The curve opens downward and the vertex is the maximum point on the graph.
F(x) - c
(p + q)/5
The longest arc between points A and B on a circle'S diameter.

23. Which quandrant is the lower right hand?
IV
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)
1.0843 X 10^11
...multiply by 100.

24. What is the area of a regular hexagon with side 6?
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
1 & 37/132
A chord is a line segment joining two points on a circle.
2sqrt6

25. What are congruent triangles?
1
2 & 3/7
(b + c)
Triangles with same measure and same side lengths.

26. A number is divisible by 4 is...
Area of the base X height = (pi)hr^2
Its negative reciprocal. (-b/a)
Its last two digits are divisible by 4.
1

27. 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?
87.5%
0
5 OR -5
$3 -500 in the 9% and $2 -500 in the 7%.

28. 5/8 in percent?
Diameter(Pi)
62.5%
(a + b)^2
6

29. Area of a triangle?
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
1:1:sqrt2
(base*height) / 2
I

30. What is the intersection of A and B?
C = (pi)d
The set of elements found in both A and B.
12.5%
3

31. (x^2)^4
1.0843 X 10^11
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)
x^(2(4)) =x^8 = (x^4)^2
F(x + c)

32. x^6 / x^3
x^(6-3) = x^3
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
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...
Sector area = (n/360) X (pi)r^2

33. If 4500 is invested at a simple interest rate of 6% - what is the value of the investment after 10 months?
4725
Area of the base X height = (pi)hr^2
From northeast - counterclockwise. I - II - III - IV
20.5

34. Length of an arc of a circle?
(b + c)
Angle/360 x 2(pi)r
61 - 67
I

35. A cylinder has a surface area of 22pi. If the cylinder has a height of 10 - what is the radius?
12.5%
.0004809 X 10^11
An expression with just one term (-6x - 2a^2)
1

36. Which is greater? 64^5 or 16^8
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
Lies opposite the greater angle
(amount of decrease/original price) x 100%
130pi

37. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
A circle centered on the origin with radius 8.
Cd
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)
75:11

38. 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?
A circle centered at -2 - -2 with radius 3.
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
(n-2) x 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

39. Evaluate 4/11 + 11/12
9 : 25
1 & 37/132
An angle which is supplementary to an interior angle.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

40. Suppose that the graph of f(x) is the result of stretching y=x + 5 away from the x-axis by a factor of 2. What is the new equation for the graph f(x)?
Two angles whose sum is 180.
y = (x + 5)/2
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
6 : 1 : 2

41. 1/2 divided by 3/7 is the same as
1/2 times 7/3
A chord is a line segment joining two points on a circle.
The overlapping sections.
1:1:sqrt2

42. What percent of 40 is 22?
55%
The graph of 3(x - 1)^2 is a translation (shift) of the graph one unit or space to the right.
10! / 3!(10-3)! = 120
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

43. Formula for the area of a circle?
9 & 6/7
1 & 37/132
A = pi(r^2)
Even

44. 10^6 has how many zeroes?
62.5%
6
4096
The interesection of A and B.

45. 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?
2 & 3/7
75:11
500
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)

46. What is an isoceles triangle?
11 - 13 - 17 - 19
Undefined
Two equal sides and two equal angles.
Divide by 100.

47. What is the graph of f(x) shifted right c units or spaces?
F(x-c)
48
Its last two digits are divisible by 4.
A 30-60-90 triangle.

48. x^4 + x^7 =
x^(4+7) = x^11
1.7
20.5
A tangent is a line that only touches one point on the circumference of a circle.

49. What is the side length of an equilateral triangle with altitude 6?
4.25 - 6 - 22
62.5%
Two angles whose sum is 90.
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...

50. What is the ratio of the sides of a 30-60-90 triangle?
1:sqrt3:2
The overlapping sections.
Two angles whose sum is 180.
4.25 - 6 - 22