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. How to find the area of a sector?
x^(4+7) = x^11
The set of elements found in both A and B.
Angle/360 x (pi)r^2
0

2. The slope of a line perpendicular to (a/b)?
Two equal sides and two equal angles.
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
Its negative reciprocal. (-b/a)
52

3. 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)?
A reflection about the axis.
28. n = 8 - k = 2. n! / k!(n-k)!
90
y = (x + 5)/2

4. What is the 'Solution' for a set of inequalities.
The overlapping sections.
The curve opens downward and the vertex is the maximum point on the graph.
Factors are few - multiples are many.
Two angles whose sum is 90.

5. When the 'a' in a parabola is positive....
F(x + c)
18
The curve opens upward and the vertex is the minimal point on the graph.
28. n = 8 - k = 2. n! / k!(n-k)!

6. What is the measure of an exterior angle of a regular pentagon?
A grouping of the members within a set based on a shared characteristic.
72
The sum of its digits is divisible by 3.
G(x) = {x}

7. How to determine percent increase?
A = I (1 + rt)
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
(amount of increase/original price) x 100%
Sector area = (n/360) X (pi)r^2

8. Volume for a cylinder?
18
The sum of digits is divisible by 9.
Area of the base X height = (pi)hr^2
A grouping of the members within a set based on a shared characteristic.

9. What is the area of a regular hexagon with side 6?
The point of intersection of the systems.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
1
3/2 - 5/3

10. Legs 6 - 8. Hypotenuse?
1:1:sqrt2
10
A grouping of the members within a set based on a shared characteristic.
4a^2(b)

11. What is the empty set?
A set with no members - denoted by a circle with a diagonal through it.
2
Expressing a number as the product of a decimal between 1 and 10 - and a power of 10.
1

12. What does the graph (x+2)^2 + (y+2)^2 = 9 look like?
A circle centered at -2 - -2 with radius 3.
10! / (10-3)! = 720
(b + c)
(amount of decrease/original price) x 100%

13. Surface area for a cylinder?
Two angles whose sum is 180.
The sum of digits is divisible by 9.
2(pi)r^2 + 2(pi)rh
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]

14. What is the 'union' of A and B?
1 & 37/132
A = pi(r^2)
10! / 3!(10-3)! = 120
The set of elements which can be found in either A or B.

15. Can the input value of a function have more than one output value (i.e. x: y - y1)?
A reflection about the axis.
61 - 67
No - the input value has exactly one output.
An infinite set.

16. Which quadrant is the upper left hand?
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
(amount of decrease/original price) x 100%
II
$3 -500 in the 9% and $2 -500 in the 7%.

17. How many digits are there between the decimal point and the first even digit in the decimal equivalent of 1/[(2^8)(5^3)]
0
2.592 kg
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
20.5

18. How many sides does a hexagon have?
...multiply by 100.
53 - 59
72
6

19. What is the graph of f(x) shifted downward c units or spaces?
The longest arc between points A and B on a circle'S diameter.
18
F(x) - c
9 & 6/7

20. x^2 = 9. What is the value of x?
13
3 - -3
413.03 / 10^4 (move the decimal point 4 places to the left)
An expression with just one term (-6x - 2a^2)

21. What is an arc of a circle?
180 degrees
An arc is a portion of a circumference of a circle.
The greatest value minus the smallest.
...multiply by 100.

22. a^2 - b^2 =
The union of A and B.
(a - b)(a + b)
A = I (1 + rt)
Yes. [i.e. f(x) = x^2 - 1

23. Simplify 9^(1/2) X 4^3 X 2^(-6)?
3
Lies opposite the greater angle
3 - -3
Two equal sides and two equal angles.

24. 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?
27^(-4)
48
Its negative reciprocal. (-b/a)
A set with no members - denoted by a circle with a diagonal through it.

25. Define a 'monomial'
Angle/360 x (pi)r^2
An expression with just one term (-6x - 2a^2)
The angle intersecting the circumference is always the largest angle - and is always 90 degrees.
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.

26. 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?
13
N! / (k!)(n-k)!
41 - 43 - 47
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)

27. What is the name for a grouping of the members within a set based on a shared characteristic?
x^(4+7) = x^11
Use Pythagorean theorem twice. (Once across the surface and then a is the diagonal of surface and b is an edge).
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 subset.

28. What is the slope of a vertical line?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

29. Can you simplify sqrt72?
Its divisible by 2 and by 3.
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.
I
1.0843 X 10^11

30. Formula to find a circle'S circumference from its diameter?
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
$3 -500 in the 9% and $2 -500 in the 7%.
C = (pi)d
Yes. [i.e. f(x) = x^2 - 1

31. 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
An isosceles right triangle.
23 - 29
Two angles whose sum is 180.

32. What is the set of elements found in both A and B?
130pi
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
The interesection of A and B.
1

33. Area of a triangle?
Its last two digits are divisible by 4.
The interesection of A and B.
(p + q)/5
(base*height) / 2

34. In a regular polygon with n sides - the formula for the sum of interior angles
1
11 - 13 - 17 - 19
(n-2) x 180
A reflection about the origin.

35. What is the common monomial factor in the expression 4(c^3)d - (c^2)(d^2) + 2cd?
12sqrt2
2 & 3/7
Cd
Undefined - because we can'T divide by 0.

36. 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?
288 (8 9 4)
(amount of increase/original price) x 100%
1
9 : 25

37. Evaluate and write as a mixed number: 2/7 - 3/21 + 2 & 4/14
F(x-c)
Factors are few - multiples are many.
2 & 3/7
5 OR -5

38. What number between 70 & 75 - inclusive - has the greatest number of factors?
72
F(x) - c
The set of output values for a function.
18

39. 1:sqrt3:2 is the ratio of the sides of what kind of triangle?
A 30-60-90 triangle.
Circumference = Diameter(pi). Use pythagorean theorem to find the diagonal of the square (the diameter).
x= (1.2)(.8)lw
x(x - y + 1)

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.
Two angles whose sum is 180.
6
1:sqrt3:2

41. a^2 + 2ab + b^2
Undefined
(a + b)^2
4.25 - 6 - 22
1.7

42. Describe the relationship between the graphs of x^2 and (1/2)x^2
3sqrt4
The set of output values for a function.
The second graph is less steep.
All real numbers which can'T be expressed as a ratio of two integers - positive and negative (pi - -sqrt3)

43. 200 <_ x <_ 300. How many values of x are divisible by 5 & 8?
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16
90pi
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
3

44. Formula for the area of a sector of a circle?
(a + b)^2
Sector area = (n/360) X (pi)r^2
9 & 6/7
... the square of the ratios of the corresponding sides.

45. A company places a 6-symbol code on each product. The code consists of the letter T - followed by 3 numerical digits - and then 2 consonants (Y is a conson). How many codes are possible?
The shortest arc between points A and B on a circle'S diameter.
441000 = 1 10 10 10 21 * 21
54sqrt3. (divide the hexagon into 6 congruent equilateral triangles.
The objects within a set.

46. What is an isoceles triangle?
1/2 times 7/3
4725
A reflection about the axis.
Two equal sides and two equal angles.

47. 10^6 has how many zeroes?
6
(b + c)
75:11
IV

48. 1/2 divided by 3/7 is the same as
The point of intersection of the systems.
An expression with just one term (-6x - 2a^2)
C = 2(pi)r
1/2 times 7/3

49. a^0 =
13pi / 2
x(x - y + 1)
Undefined - because we can'T divide by 0.
1

50. Reduce: 4.8 : 0.8 : 1.6
2^9 / 2 = 256
F(x) + c
6 : 1 : 2
130pi