GMAT Math Formulas List

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To achieve a good score on the math section, it is essential that you memorize the necessary GMAT math formulas. Below, you will find a free review sheet full of formulas that are used frequently on the quantitative section.

Algebra Formulas

Exponential Equations

xⁿ*x^m = x^{n + m}
(xⁿ)/(x^m) = x ^{n - m}
(x/y)ⁿ = (xⁿ)/(yⁿ)
xⁿ*yⁿ = (xy)ⁿ
(x^y)^z = x^yz
x^-n = 1/(xⁿ)
1ⁿ = 1
x⁰ = 1
0ⁿ = 0, except 0⁰ = 1 or undefined
F_V = C_V(1 + g)^T
Examples

Quadratic Equations

ax² + bx + c = 0.

Examples

Interest

Simple Interest = P*r*t
P = starting principle; r = annual interest rate; t = number of years
Annual Compound Interest = P(1+r)^t
Compound Interest = P(1 + r/x)^xt x = number of times the interest compounds over the year

Other

Distance = Rate*Time
Wage = Rate*Time

Arithmetic Formulas

Combinatorics

Combinations:_nC_k = n!/((n-k)k!)!
Permutations:_nP_k = n!/(n-k)!
Circular: (n-1)!
k = number of objects selected from a pile of n objects
n = total number of objects from which k objects can be selected

Fractions

(a/b)/(c/d) = (a/b) * (d/c)

Percents

Percent Change, as a decimal = (New - Old)/Old
N = (1 + G)O; N = New Value, 0 = Old Value, G = Growth Rate as decimal

Probability

Probability that event E occurs = P(E) = (Number of outcomes in E) / (Total number of possible outcomes)
P(not E) = 1 - P(E)
P(E or F) = P(E) + P(F) - P(E and F)
P(E and F) = P(E)P(F)

Number Properties

(Odd)(Even) = Even
(Odd)(Odd) = Odd
(Even)(Even) = Even

(Odd) ± (Even) = Odd
(Odd) ± (Odd) = Even
(Even) ± (Even) = Even

(Positive)(Positive) = Positive
(Positive)(Negative) = Negative
(Negative)(Negative) = Positive
(Positive)/(Negative) = Negative
(Positive)/(Positive) = Positive
(Negative)/(Negative) = Positive

Statistics

Average (Arithmetic Mean): (sum of all numbers)/(number of numbers)
Median: the middle number (or average of the two middle numbers if there are an even number of figures) when all values are arranged in ascending order
Mode: the mos frequently occuring value in a dataset

Geometry Formulas

Angles

Sum of Interior Angles of Polygon = (n-2)(180)
n = number of sides of a polygon
Central Angle = 2(Inscribed Angle)

Area

Square: A = a²
Rectangle: A = lw
Parallelogram: A = bh
Trapezoid: A = .5(a+c)h, where a and c are the lengths of the parallel sides

Circles

π = pi = 3.1415
Area: A = πr²
Circumference: C = 2πr
Central Angle = 2(Inscribed Angle)
Area of Sector = (x/360)πr²

Perimeter

Square: P = 4l
Rectangle: P = 2w + 2l
Parallelogram: P = 2b + 2a, where a and b are the lengths of the non-parallel sides
Circle: P = 2πr

Triangles

Area: A = .5bh
Pythagorean Theorem: A² + B² = C² where A = one leg, B = the other leg, C = hypotenuse

Volume

Cube: V = a³ where a is the length of a side
Rectangular Solid: V = hwl
Cylinder: V = πr²h