​Formulas for GRE Math Section

​The GRE (Graduate Record Examination) is a standardized test required for admission to many graduate schools. The quantitative section of the test is designed to assess basic math skills, understanding of elementary mathematical concepts, and the ability to reason quantitatively. Below is an exhaustive list of mathematical formulas that will come in handy when studying for the GRE.
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Arithmetic Formulas
  1. Addition and Subtraction of Fractions: a/b ± c/d = (ad ± bc) / bd
  2. Multiplication of Fractions: (a/b) * (c/d) = ac / bd
  3. Division of Fractions: (a/b) ÷ (c/d) = ad / bc
  4. Percentage: Percent Change = (New - Old) / Old * 100
  5. Average: Average = (Sum of items) / (Number of items)
  6. Weighted Average: Weighted Average = (w1x1 + w2x2 + w3x3 + … + wnxn) / (w1 + w2 + w3 + … + wn)
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Algebra Formulas
  1. Laws of Exponents: a. x^m * x^n = x^(m+n) b. (x^m) / (x^n) = x^(m-n) c. (x^m)^n = x^(m*n) d. x^0 = 1
  2. Quadratic Formula: For equation ax^2 + bx + c = 0, x = [-b ± sqrt(b^2 - 4ac)] / (2a)
  3. Factoring Quadratics: a^2 - b^2 = (a - b)(a + b)
  4. Sum and Product of Roots: For equation ax^2 + bx + c = 0, sum of roots = -b/a and product of roots = c/a

Geometry Formulas
  1. Area of a Rectangle = length * width
  2. Perimeter of a Rectangle = 2(length + width)
  3. Area of a Triangle = 0.5 * base * height
  4. Pythagorean Theorem: a^2 + b^2 = c^2
  5. Area of a Circle = πr^2
  6. Circumference of a Circle = 2πr
  7. Area of a Square = side^2
  8. Perimeter of a Square = 4 * side
  9. Volume of a Cube = side^3
  10. Volume of a Cylinder = πr^2h

Probability Formulas
  1. Addition Rule: P(A or B) = P(A) + P(B) - P(A and B)
  2. Multiplication Rule: P(A and B) = P(A) * P(B|A)

Counting Methods
  1. Permutation: nPr = n! / (n-r)!
  2. Combination: nCr = n! / [r!(n-r)!]
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Please note that these formulas are just part of the skills you need to successfully complete the GRE quantitative section. Always make sure you understand the underlying concepts and how to apply the formulas in solving problems. You can test your knowledge by taking a GRE practice test. Good luck with your exam prep!