Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GRE Math and Verbal Tips > GRE Math Tips > Flashcards

GRE Math Tips Flashcards

You may prefer our related Brainscape-certified flashcards:
GRE® Vocabulary flashcards GRE® Psychology flashcards
1
Q

an arrangement of items is a

A

an arrangement of items is a permutation of items

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

a distinct set of items is another way of saying

A

combination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

differentiate between problems that ask you to determine standard deviations and those problems that ask you to determine x*standard deviation

A

x*standard deviation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

to square both sides of an equality, make sure both are positive

A

make sure both are positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

taking the square root results in

A

2 solutions, a positive solution and a negative solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

answer QC questions involves

A

algebraic manipulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

mean (statistic)

A

= (number of entries)/N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

median (statistic)

A

middle number on an ordered list

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

if a list has an even number of items, the median is the

A

average of the 2 middle numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

mode (statistics)

A

the most often appearing number in list

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

regression line n.

A

best fit line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

double matrix method

A

use for males and females when describing percentages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

a negative base to an even power is

A

positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

b^s=b^t

A

s=t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

x^2>x^6?

A

cannot be determined

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when the square root sign is written, it means

A

the positive root only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

x^2 means

A

the positive root and the negative root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

if you yourself take the square root, them

A

you must include both signs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

square root of 225

A

15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

square root of 169

A

13

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

square root of 121

A

11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

square root of 196

A

14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what produces extraneous roots

A

undoing the radical or squaring the radical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

to determine numbers greater than a square root than is a prime factor

A

take the square root of everything

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

mutually exclusive events in probability

A

means one doesn’t depend on the other, it means that it is impossible for both of them to happen together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

P(A or B) mutually exclusive

A

P(A) + P(B)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

generalized RULE for P(A or B)

A

P(A) + P(B)-P(A and B)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

independent events (probability)

A

one event does not influence another even

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

two independent events A and B P(A and B)

A

simplified and rule P(A) * P(B)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

independent events P(A and B)

A

use simple rule P(A) * P(B)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

independent events are NOT mutually exclusive

A

TRUE: mutually exclusive influence one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

events A and B are not independent events, one happening changes the probability of the other happening

A

conditional probabilities: P(A | B)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

P(A and B) when NOT INDEPENDENT

A

P(A and B)=P(B)*P(A|B) or

P(A and B)=P(A)*P(B|A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

complement solutions (probability)

A

if the math problem asks you “at least one”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

determine the number of integers between x and y inclusive

A

y-x+1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

when a probability questions states AT LEAST

A

determine the complement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

“and” and “or” in combinatorics

A

“or” means add and “and” means multiply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

for combinatorics, each slot can represent different groups

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

fundamental counting principle

A

nnn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

alternative counting method

A

number of arrangements that obey rule versus number of arrangements that do not obey rule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

counting problem that involves interaction with one another

A

divide by 2 to eliminate repetition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

a problem that asks you to create different sets, meaning how many combinations

A

use combinations without repetition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

for counting problems, “and” means and “or” means

A

multiply and add

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

use the FCP whenever possible starting with the most restrictive parts

A

count the most restrictive parts first

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

every 9 minutes beginning at 7:04 a train departs

A

first train leaves 7:04, next train leaves at 7:13

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

the absolute value is

A

the distance of the number from the origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

continuous probability distribution has a total area of

A

100% or 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

an isosceles triangle has equal sides

A

thus area can be calculated by taking the square root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

if polygon is inscribed in circle, the area

A

is constant regardless of how you draw it as long as its inscribed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

the largest possible rectangle inscribed inside a circle is a

A

square

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

2 chords in a triangle that form a triangle with the diameter form a

A

90 deg angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

standard deviation

A

square root ((1/N)*sum of difference squared)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

triangle inequality

A

sum of any two sides must be bigger than the 3rd side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

3,4,5

A

triangle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

5,12,13

A

triangle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

area of trapezoid

A

(b1+b2/2)h

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

a prime number

A

a number greater than 1 that has no positive divisors other than 1 and itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

to cancel two square roots, the inside

A

of each square root must be the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

a divisor is comprise of all the

A

prime numbers raised to powers

60
Q

an odd divisor cannot contain any

A

2

61
Q

1st quartile is

A

numbers lower than the median of the 1st half

62
Q

to determine the larger of two fractions,

A

cross multiply

63
Q

equation of a circle,

A

(x-h)^2 +(y-k)^2=r^2

64
Q

K is a multiple of a

A

smaller number

65
Q

dividend /divisor

A

quotient

66
Q

divisibility by 11 if

A

difference of alternating is divisible by 11

67
Q

the mean and mode are the same when

A

set is symmetric and even

68
Q

add numbers from 1 to n

A

n(n+1)/2

69
Q

in a right triangle, side in front of 90 angle is the biggest

A

this makes it easy to compare two triangles sharing a side

70
Q

for math problems that ask you to select answer that can be true

A

use scenarios when it cannot be possibly true or use logic to rule things out (i.e. xy=0 or xy cannot equal 0)

71
Q

The total number of people in honor society at Melpomene High School, regardless of other activities, is approximately

A

regardless mean it is okay to include honor society number + other activities

72
Q

what percent higher than the total number of people in honor society at Thalia High School, regardless of other activities?

A

percent higher means calculate the percentage difference

73
Q

compound interest

A

P(1+r/n)^nt

74
Q

trillion

A

10^12

75
Q

billion

A

10^9

76
Q

million

A

10^6

77
Q

in arithmetic

A

pay close attention to units when converting

78
Q

logic-based QC problems have the following options unless EXPLICITlY stated

A
  1. variables can both be zero
  2. variables can be positive and/or negative decimals
  3. variables can be positive and/or negative integers
79
Q

a,b,c, and d, a is half of b, which is third of c

A

the which is applies ONLY to the b

80
Q

x^2-y^2=0

A

x=y is not necessarily the case, taking the square root of both sides x^2=y^2 yields |x|=|y|

81
Q

QC problems that ask you to select the choices that MUST BE TRUE,

A

start with strategy ABC, then pick scenarios that are opposite to listed choices

82
Q

how many positive divisors does a number have

A
  1. perform prime factorization

2. (n+1)(n+1)…

83
Q

determine cost of tax plus price of item

A

price*1.tax

84
Q

for a set of consecutive numbers, the mean BLANK the median

A

equals

85
Q

5/6

A

.833

86
Q

1/8

A

.125

87
Q

when one section of a pie chart increases percentage while everything stays the same

A

new percentage/(100+difference between new percentage and old percentage)

88
Q

triangle identity 5, 12, __

A

5, 12, 13

89
Q

triangle identity 8, 15, __

A

8, 15, 17

90
Q

measure of inscribed angle in circle

A

=0.5*chord

91
Q

measure of central angle

A

=measure of chord

92
Q

an inscribed angle inside a semicircle is a

A

right triangle

93
Q

angle exscribed outside circle

A

bigger chord minus smaller chord

94
Q

2 times any integer

A

equals an even number

95
Q

if you have 3 ways to do one thing and 3 ways to do another thing,

A

multiply 3*3 to determine the number of possibilities of both groups together according to FCP

96
Q

the range of a set

A

{a->c}

97
Q

30-60-90

A

x,2x,x^1/3

98
Q

equation of line

A

y-y=m(x-x)

99
Q

the number zero is

A

even

100
Q

the number zero is neither

A

positive or negative

101
Q

triangle rule

A

A-B

102
Q

select ALL POSSIBLE CHOICES

A

select answers that may work some of the time

103
Q

range=

A

biggest - smallest

104
Q

profit=

A

=revenue - cost

105
Q

prime factorization

A

numbers when multiplied together give you the original number

106
Q

rational expression

A

ratio of algebraic expressions

107
Q

area of equilateral triangle

A

s^2(square root of 3 / 4)

108
Q

number of odd divisors

A

select only odd prime factors

109
Q

number of even prime numbers

A

total - odd

110
Q

n consecutive integers always contains

A

one number divisible by n

111
Q

if n is odd

A

the sum of set n consecutive numbers will always contain a number divisible by n

112
Q

triangle identity 7,24,25

A

7,24,25

113
Q

sum of numbers from 1 to n

A

n (n+1)/2

114
Q

even numbers from 1 to n

A

n(n+2)/4

115
Q

sum of odd numbers for 1 to n

A

(n+1)^2/4

116
Q

squaring both sides of a solution may introduce

A

extraneous solutions

117
Q

a natural number is a

A

positive integer

118
Q

if a number is less than 100 and not divisible by 2,3,5,7,

A

than it is prime

119
Q

counting strategy

A
  1. restrictions? (start with most restrictive item)
  2. alternative method?
  3. counting identical items?
  4. stages?
  5. define n
  6. repetition allowed?
  7. distinct sets desired?
120
Q

SD decreases if you

A

add 2 symmetric numbers smaller than SD

121
Q

SD increases if you

A

add 2 symmetric numbers larger than SD

122
Q

bello curve left or right percentages

A

34% then 13.5%

123
Q

min, 1st quartile, median, third quartile, max

A

5-number summary

124
Q

interquartile range

A

Q3-Q1

125
Q

if a score is in the xth percentile,

A

the score is larger than p% of the scores in the distribution

126
Q

GCF

A

list the prime factors of each number, multiply those factors both have in common, if there are no common factors, the GCF is 1

127
Q

greatest common divisor of two numbers

A

the smallest of two numbers

128
Q

least common multiple of two numbers

A

the greatest of two numbers

129
Q

for double x y-axis graphs

A

make sure you extrapolate using the correct y-axis

130
Q

the product of 2 consecutive numbers equals

A

an even number

131
Q

is the number 0 even or odd

A

even

132
Q

(-1)^n

A

positive if n is even and negative if n is odd

133
Q

slope-intercept form

A

y=mx+b

134
Q

(divisor*quotient)+R=

A

dividend

135
Q

x^2-y^2=

A

x^2-2xy+y^2

136
Q

supplementary angles

A

sum is 180

137
Q

probability = arrangements/arrangements

A

true sometimes

138
Q

once the bases are the same you can

A

equate the exponents

139
Q

when comparing ages at different points in time

A

equate the ages of a single person over time to solve

140
Q

if a problem gives you the percentage or percentages,

A

make sure you can take the percentage of the number so you end up with an integer

141
Q

if a math problem gives you 2 variables,

A

put one variable in terms of the other and solve

142
Q

just because 2 triangles share the same angle

A

doesn’t mean the opposing sides are equal to each other

143
Q

different committees means

A

combinations

144
Q

sometimes, you may need to construct b^2+2bh+h^2

A

when given b^2+h^2

145
Q

exception to the Mississippi rule

A

if the question doesn’t ask you to use all the spaces available and restricts you to using 3 spaces, them determine the number of combos with repeats then subtract the number of repeats from the word and calculate the number of permutations

GRE Math and Verbal Tips (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions