These are flashcards someone made to review for the GRE quantitative section. Memorizing these could save you some time on the GRE.

Arc length
X = Measure of interior angle
--------------- ---------------------------------
Circumference of circle 360

Area of a circle
A=pi*(r^2)

Area of a rectangle
A=l*w

Area of a sector
X = Measure of interior angle
---------------- ----------------------------------
Area of Circle 360

Area of a trapezoid
A= (1/2)h*(a+b) where a is the length of the bottom base and b is the length of the top base.

Area of a triangle
A= (1/2)b*h

Area of parallelogram
A=b*h

Circumference of a Circle
c=2pi r OR d*pi

Convert 12.5% to a fraction
1/8

Convert 16.66% to a fraction
1/6

Convert 20% to a fraction
1/5

Convert 25% to a fraction
1/4

Convert 33.33% to a fraction
1/3

Convert 40% to a fraction
2/5

Convert 60% to a fraction
3/5

Convert 66.66% to a fraction
2/3

Convert 75% to a fraction
3/4

Convert 80% to a fraction
4/5

Convert 83.33% to a fraction
5/6

Find distance when given time and rate
d=rt so r= d/t and t=d/r

Find hypotenuse of a right triangle given 2 side lengths
Pythagorean Theorem: h^2= (S1)^2 + (S2)^2

First 10 prime #s
2, 3, 5, 7, 11, 13, 17, 19, 23, 29

How to find the average of consecutive #s
Take the average of the largest and smallest # in the set. (i.e. for the set of consecutive #s 5....172 would be (172+5)/(2)= 88.5)

How to find the sum of consecutive #s
Sum= (Average of Consecutive #s) * (# of terms in set)

How to recognize a # as a multiple of 3
The sum of the digits is a multiple of 3

How to recognize a # as a multiple of 4
The last 2 digits are a multiple of 4. (i.e 144. 44 is a multiple of 4, so 144 must also be a multiple of 4.)

How to recognize a # as a multiple of 9
The sum of the digits is a multiple of 9.

How to recognize a multiple of 6
Sum of digits is a multiple of 3 and the last digit is even.

How to recognize if a # is a multiple of 12
The sum of the digits it a multiple of 3 and the last two digits is a multiple of 4. (i.e 144: 1+4+4=9 which is a multiple of 3, and 44 is a multiple of 4, so 144 is a multiple of 12.)

Perfect Squares 1-15
1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225

Perimeter of a rectangle
P= 2L + 2w

Quadratic Formula
X= -b (+/-) Sqrroot [(b^2) -4ac)]
-----------------------------------
2a

Side lengths of a 30-60-90 right triangle
1-sqrroot of 3-2

Side lengths of a 45-45-90 right triangle
1-1-sqrroot of 2

Slope given 2 points
m= (Y1-Y2)/(X1-X2)

Surface area of a rectangular solid
SA= 2( Lw + L h + w*h)

Surface area of a right circular cylinder
2(pi(r^2))+ 2 pir h

Surface area of a sphere
SA= 4pi (r^3)

Volume of a rectangular box
V=Lw h

Volume of a right circular cylinder
pi(r^2) h

Volume of a sphere
V=(4/3)pi (r^3)

When asked to find the distance between 2 points on a graph use this formula...
Distance formula. Distance= Sqrareroot[((Xa-Xb)^2) + ((Ya-Yb)^2)]

When dividing exponential #s with the same base, you do this to the exponents...
Subtract them. i.e (5^7)/(5^3)= 5^4

When multiplying exponential #s with the same base, you do this to the exponents...
Add them. i.e. (5^7) * (5^3) = 5^10

When solving an inequality, flip the sign when you....
divide or multiply both sides by a NEGATIVE number