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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. 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?
The curve opens downward and the vertex is the maximum point on the graph.
A 30-60-90 triangle.
Even
$3 -500 in the 9% and $2 -500 in the 7%.

2. Evaluate 4/11 + 11/12
x^(4+7) = x^11
13
Area of the base X height = (pi)hr^2
1 & 37/132

3. 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?
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
10! / 3!(10-3)! = 120
9 : 25
An isosceles right triangle.

4. Which quadrant is the upper left hand?
A chord is a line segment joining two points on a circle.
II
8
A subset.

5. Describe the relationship between the graphs of x^2 and (1/2)x^2
4a^2(b)
The second graph is less steep.
180 degrees
20.5

6. What are the integers?
Undefined
All numbers multiples of 1.
2^9 / 2 = 256
When we need to avoid having a zero in the denominator or avoid taking the square root of a number.

7. Formula for the area of a circle?
A grouping of the members within a set based on a shared characteristic.
An expression with just one term (-6x - 2a^2)
A = pi(r^2)
Its negative reciprocal. (-b/a)

8. What are the rational numbers?
All numbers which can be expressed as a ratio of two integers. (All integers and fractions.) (-2 - 1 - .25 - 1/2)
Undefined - because we can'T divide by 0.
No - only like radicals can be added.
(a + b)^2

9. Circumference of a circle?
Arc length = (n/360) x pi(2r) where n is the number of degrees.
Sqrt 12
Diameter(Pi)
1

10. 3/8 in percent?
37.5%
[(7+ sqrt93) /2] - [(7 - sqrt93) / 2]
F(x-c)
13pi / 2

11. 60 < all primes <70
Its divisible by 2 and by 3.
61 - 67
A circle centered at -2 - -2 with radius 3.
12sqrt2

12. What is a parabola?
90pi
4725
37.5%
Ax^2 + bx + c where a -b and c are constants and a /=0

13. 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?
2sqrt6
10! / 3!(10-3)! = 120
12sqrt2
3 - -3

14. What is the ratio of the sides of a 30-60-90 triangle?
A chord is a line segment joining two points on a circle.
1:sqrt3:2
90pi
1

15. What is the 'Restricted domain of a function'?
Angle/360 x 2(pi)r
No - the input value has exactly one output.
90pi
When the function is not defined for all real numbers -; only a subset of the real numbers.

16. Define an 'expression'.
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)
72
441000 = 1 10 10 10 21 * 21
Ax^2 + bx + c where a -b and c are constants and a /=0

17. Define a 'Term' -
1/a^6
The shortest arc between points A and B on a circle'S diameter.
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)
Factors are few - multiples are many.

18. Reduce: 4.8 : 0.8 : 1.6
6 : 1 : 2
5 OR -5
180
Yes - because you can factor out a perfect square (36). Sqrt(36 x 2) = sqrt36 X sqrt2 = 6sqrt2.

19. How to determine percent increase?
No - only like radicals can be added.
(amount of increase/original price) x 100%
9 : 25
28. n = 8 - k = 2. n! / k!(n-k)!

20. A number is divisible by 4 is...
3
Its negative reciprocal. (-b/a)
Its last two digits are divisible by 4.
23 - 29

21. Pi is a ratio of what to what?

22. 0^0
Undefined
1 & 37/132
2.592 kg
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a

23. 7/8 in percent?
Area of the base X height = (pi)hr^2
Even
1
87.5%

24. For what values should the domain be restricted for the function f(x) = sqrt(x + 8)
8
Its last two digits are divisible by 4.
G(x) = {x}
The sum of its digits is divisible by 3.

25. How to find the area of a sector?
Angle/360 x (pi)r^2
A subset.
6
Pi is the ratio of a circle'S circumference to its diameter.

26. To convert a decimal to a percent...
The set of elements found in both A and B.
1
...multiply by 100.
28. n = 8 - k = 2. n! / k!(n-k)!

27. 5/6 in percent?
62.5%
Diameter(Pi)
83.333%
x^(4+7) = x^11

28. Convert 0.7% to a fraction.
90pi
Triangles with same measure and same side lengths.
7 / 1000
16^8 - 64^5 = (4^3)^5 = 4^15 - 16^8=(4^2)^8 = 4^16

29. If the two sides of a triangle are unequal then the longer side...
5 OR -5
(amount of increase/original price) x 100%
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15
Lies opposite the greater angle

30. If 8 schools are in a conference - how many games are played if each team plays each other exactly once?
13
180
x = [(-b)+/- (sqrt b^2 - 4ac)]/2a
28. n = 8 - k = 2. n! / k!(n-k)!

31. Define a 'monomial'
Even
71 - 73 - 79
41 - 43 - 47
An expression with just one term (-6x - 2a^2)

32. x^2 = 9. What is the value of x?
6
6 : 1 : 2
3 - -3
(6 x 2)(sqrt3 x sqrt5) = 12sqrt15

33. The four angles around a point measure y - 2y - 35 and 55 respectively. What is the value of y?
90
A reflection about the origin.
28. n = 8 - k = 2. n! / k!(n-k)!
F(x) - c

34. P and r are factors of 100. What is greater - pr or 100?
11 - 13 - 17 - 19
(a - b)(a + b)
A chord is a line segment joining two points on a circle.
Indeterminable.

35. What is the sum of the angles of a triangle?
A grouping of the members within a set based on a shared characteristic.
180 degrees
The direction of the inequality is reversed.
A reflection about the origin.

36. 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?
The curve opens downward and the vertex is the maximum point on the graph.
500
90 degrees
61 - 67

37. If Madagascar'S exports totaled 1.3 billion in 2009 - and 4% came from China - what was the value in millions of the country'S exports to China?
52
Its divisible by 2 and by 3.
10
x^(4+7) = x^11

38. The objects in a set are called two names:
The third side is greater than the difference and less than the sum.
C = 2(pi)r
Members or elements
Area of the base X height = (pi)hr^2

39. 1:1:sqrt2 is the ratio of the sides of what kind of triangle?
(a + b)^2
An isosceles right triangle.
4:5
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)

40. A brick with dimensions 10. 15 and 25 weighs 1.5 kg. A second brick (same density) has dimensions 12 - 18 - and 30. What is the weight of the second brick?
An angle which is supplementary to an interior angle.
2.592 kg
The union of A and B.
61 - 67

41. What is the measure of an exterior angle of a regular pentagon?
72
Two equal sides and two equal angles.
F(x) - c
11 - 13 - 17 - 19

42. To multiply a number by 10^x
1 & 37/132
13
Move the decimal point to the right x places
75:11

43. What is a set with no members called?
The empty set - denoted by a circle with a diagonal through it.
(base*height) / 2
PEMDAS (Parentheses Exponents Multiplication/Division Addition/Subtraction)
From northeast - counterclockwise. I - II - III - IV

44. What is an isoceles triangle?
Two equal sides and two equal angles.
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.
0
Infinite.

45. Which is greater? 27^(-4) or 9^(-8)
The interesection of A and B.
A set with a number of elements which can be counted.
12! / 5!7! = 792
27^(-4)

46. What is the formula for computing simple interest?
F(x + c)
A circle centered on the origin with radius 8.
9 : 25
A = I (1 + rt)

47. 10^6 has how many zeroes?
The second graph is less steep.
6
The set of output values for a function.
Undefined - because we can'T divide by 0.

48. In similar hexagons - the ratio of the areas is 16:25. What is the ratio of their corresponding sides?
0
The two xes after factoring.
4:5
A subset.

49. Length of an arc of a circle?
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.
4725
Angle/360 x 2(pi)r
The set of input values for a function.

50. For similar triangles - the ratio of their corresponding sides is 2:3. What is the ratio of their areas?
4:9. The ratio of the areas of two similar triangles equals the square of the ratio of the corresponding sides.
Indeterminable.
41 - 43 - 47
The sum of digits is divisible by 9.