Sum of interior angles of a polygon: 180(n-2) where n is the # of sides
Combo Problems: Manipulations
The GMAT often asks you to solve for a combination of variables, called COMBO problems.
For example, a question might ask, what is the value of x +y?
In these cases, since you are not asked to solve for one specific variable, you should generally
NOT try to solve for the individual variables right away. Instead, you should try to
manipulate the given equation(s) so that the COMBO is isolated on one side of the equation.
Only try to solve for "the individual variables after you have exhausted all other
Types of Function Problems on the GMAT:
1. Numerical Substitution 2. Variable Substitution 3. Compound Functions 4. Functions with Unknown Constants 5. Function Graphs 6. Special Functions * Direct Proportionality * Indirect Proportionality * Linear Growth
Popular on GMAT: Exterior Angles of a Triangle
exterior angle is equal to the sum of the two opposite interior angles of the triangle
What is the easiest way to deal with tough division on the GMAT?
Factor the numerator and denominator into primes and cancel
Many GMAT word problems involve the total price or value of a mixed set of goods. On such problems, you should be able to write two different types of equations right away:
* Relate the QUANTITIES or numbers of different goods: Sum of these numbers = Total * Relate the total VALUES of the goods (or their total cost, or the revenue from their sale): * Money spent on one good = Price x Quantity * Sum of money spent on all goods = Total Value
Formula for Computing the $ amount of Accrued Interest
(Principal x Rate x Time) ____________________________
If a price is discounted by N percent, then the price becomes (100-N) percent of the original price