Brainscape's Knowledge GenomeTM

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


See full index

GRE > GRE Math > Flashcards

GRE Math Flashcards

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

Adjacent Squares (Addition)

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

Slope

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

Point-Slope Form

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

Slope-Intercept Form

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

When to use estimation?

A

Multiple choice answers when answers are far apart

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

Adjacent Squares (Subtraction)

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

Squares of 5

A
  1. Number to be squared: 752
  2. Remove the 5: 75 -> 7
  3. Add one to the remaining digit: 7 -> 8
  4. Multiply the two: 7 * 8 = 56
  5. Put this in front of 25: 752 = 5625
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Dividing by 5

A
  • Double a number then divide by 10
  • Divide by 10 then double
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Doubling & Halving

A
  • Dividing and multiplying factors by 2 to get easier factors
  • You can do this multiple times
  • Example
    • Suppose 16 * 35
      • 16 / 2 = 8
      • 35 * 2 = 70
      • 70 * 8 = 560
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Squaring Multiples of 10

A
  • Square the 10, square the non-10 and multiply the two
  • Example: 402 = 42 * 102 = 16 * 100 = 1600
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When to use doubling and halving with 5

A
  • A factor ends in 5 (45)
  • A factor is an odd multiple of 50 (150)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

4 Random Number Game

A
  1. Take 4 random numbers in 0-9
  2. Use all of the numbers to find all numbers in 1 - 20
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

GRE Quantitative Question Types

A
  1. Multiple Choice
  2. Multiple Answer
  3. Number Entry
  4. Quantitative Comparison
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Quantitative Comparison Answers

A

A) Quantity A is always better
B) Quantity B is always better
C) Both are always equal
D) Cannot be determined

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

QC Approximations

A
  • Use estimation
  • Compare parts instead of the whole
  • If both columns have only numbers then D can’t be the answer
  • Example
    • Q(A) 32.8% of 5,929 Q(B) 41.6% of 5,041
      • 33.3-% of 6000- = 2000-
      • 40+% of 5000+ = 2000+
      • Therefore (B)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

QC Matching Operations

A
  • Equalities: >, <, =
  • Allowable Operations
    • Add to both sides
    • Subtract from both sides
    • Multiply or divide the same positive number
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Rounding

A
  • 0 - 4 = Round Down
  • 5 - 9 = Round Up
  • Only look one place to the right when rounding
  • *10.49999 = 10
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Quantity Increase (Percentage)

A

x = Q * (1 + (P% as a decimal))

x = 230 * (1 + 0.4)

x = 230 * 1.4

x = 322

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

Quantity Decrease (Percentage)

A

x = Q * (1 - (P% as a decimal))

x = 80 * (1 - 0.7)

x = 80 * (0.3)

x = 24

20
Q

Find the Multiplier

A
21
Q

Distributive Property

A

Multiplication distributes over addition and subtraction

Works if addition/subtraction is in the numerator, but NOT the denominator

22
Q

Percent Increase Equation

A

Amount * (1 + Percent Decimal)

$425 increases by 30%

$425* (1 + 0.3) = $425 * 1.3 = $552.5

23
Q

Percent Decrease Equation

A

Amount * (1 - Pecent Decimal)

$700 decreases by 25%

$700 * (1 - 0.25) = $700 * 0.75 = $525

24
Q

Simple Interest

A
  • Each payment is paid against the original principal amount.
  • Not the way interest works, but is good for illustrating the general idea and estimation.
  • Amount = Principle + (Principle * Percent * Repetition)
    • A = P + (P*D*R)
  • Example: Bob deposits $1000 in an account that yields 5% simple interest annually.
    • 5% of $1000 = $50
    • 1 year: $1000 + $50 = $1050.00
    • 2 years: $1050 + $50 = $1100.00
    • 3 years: $1100 + $50 = $1150.00
    • Etc…
25
Q

Compound Interest

A
  • Interest percentage paid according to the current total, not the original principal, essentially stacking the amount.
  • Example: Bob deposits $1000 in an account that yields 5% compound interest annually.
    • Start = $1000
    • 1 year = 1000*(1.05) = 1050
    • 2 year = 1050*(1.05) = 1102.5
    • 3 year = 1102.5*(1.05) = 1157.625
    • Etc.
26
Q

Compound Interest Formula (Simple)

A

In y years, the principal will be multiplied by the percent increase multiplier y times. Let P be the principal and r be the multiplier. The total amount in the account after y years is given by:

27
Q

Compound Interest Multiplier

A
28
Q

Compound Interest Formula (Full)

A
29
Q

Inverse of a Fraction

A

You can always take the inverse of a numerical or variable fraction.

30
Q

Cross Multiply Fractional Equalities

A

Fractional equalities can always be cross-multiplied

31
Q

Multiply to get Equalities

A

Multiply both sides to get equalities with other equations

3w = 2x

15w = 8y

5*3w = 5*2x

15w = 10x

Therefore 10x = 8y

32
Q

Ratio

A
  • a fraction that compares part-to-whole or part-to-part
  • 6:13 = 6 for every 13
33
Q

P to Q Form (Ratios)

A

“The ratio of boys to girls is 3 to 4”

34
Q

Fraction Form (Ratios)

A

“The ratio of boys to girls is 3/4”

*This is the most useful form for problem solving

35
Q

Colon Form (Ratios)

A

“The ratio of boys to girls is 3:4”

36
Q

Idiom Form (Ratios)

A

“For every 3 boys, there are 4 girls”

37
Q

How do we solve the majority of ratio problems on the test?

A
  • set two equivalent fractions equal
  • this is an equation of the form: fraction = fraction
  • this is called as a proportion
  • 7/10 = 49/70
38
Q

Proportion

A
  • two fractions that are equal
  • fraction = fraction
  • Example: In a class, the ratio of boys to girls is 5:8. If ther are 40 girls, how many boys are there?
39
Q

Scale Factor

A
  • a number which scales or multiplies a given quantity
  • Ex: In a class, the ratio of boys to girls is 3:7. If there are 32 more girls than boys, how many boys are there?
  • 3n - 7n = 4n
  • 4n = 32
  • n = 8
  • 3n = 3*8 -> n = 24
40
Q

Portioning

A
  • adding the two ratio numbers together to get the full number that each factor is a part of
  • Ex: Boys to girls is 3:5. Boys are what fraction of the whole?
  • 3+5 = 8
  • Boys are 3/8 of the whole
41
Q

How do you solve a proportion?

A
  • cross-multiply then divide by the known number
42
Q

Absolute Quantity (Fractions)

A
  • when an actual number is present for a fractional amount you can find other absolute quantities of related fractions
43
Q

Least Common Multiple (Ratios)

A
  • use the LCM to relate ratios and solve problems
  • B:C = 3:4 & C:S = 7:11
    • LCM of 7 and 4 = 28
    • B:C = 3*7:4*7 = 21:28
    • C:S = 7*4:11*4 = 28:44
    • B:C:S = 21:28:44
44
Q

What does “x percent of” a number or fraction mean?

A

x over 100 times the number or fraction

45
Q

Compound Interest (Quarterly)

A

GRE (5 decks)

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