Formulas for GRE Quantitative Section

Perfect Squares 1-15

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

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.)

Surface area of a right circular cylinder

2(pi(r^2))+ 2pirh

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)]

Area of a rectangle

A=l*w

How to recognize a # as a multiple of 9

The sum of the digits is a multiple of 9.

Slope given 2 points

m= (Y1-Y2)/(X1-X2)

Circumference of a Circle

c=2pir OR d*pi

Volume of a sphere

V=(4/3)pi(r^3)

Area of a circle

A=pi*(r^2)

How to find the sum of consecutive #s

Sum= (Average of Consecutive #s) * (# of terms in set)

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

When solving an inequality, flip the sign when you....

divide or multiply both sides by a NEGATIVE number

Perimeter of a rectangle

P= 2L + 2w

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)

Volume of a right circular cylinder

pi(r^2)h

How to recognize a multiple of 6

Sum of digits is a multiple of 3 and the last digit is even.

Arc length

X = Measure of interior angle--------------- ---------------------------------Circumference 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.

Volume of a rectangular box

V=Lwh

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 3

The sum of the digits is a multiple of 3

Surface area of a rectangular solid

SA= 2( Lw + Lh + w*h)

Area of a sector

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

Area of parallelogram

A=b*h

Area of a triangle

A= (1/2)b*h

Surface area of a sphere

SA= 4pi(r^3)

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

First 10 prime #s

2, 3, 5, 7, 11, 13, 17, 19, 23, 29

Convert 12.5% to a fraction

08-Jan

Convert 16.66% to a fraction

06-Jan

Convert 20% to a fraction

05-Jan

Convert 25% to a fraction

04-Jan

Convert 33.33% to a fraction

03-Jan

Convert 40% to a fraction

05-Feb

Convert 60% to a fraction

05-Mar

Convert 66.66% to a fraction

03-Feb

Convert 75% to a fraction

04-Mar

Convert 80% to a fraction

05-Apr

Convert 83.33% to a fraction

06-May

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