GMAT Strategy Guide [Future Black MD MBA Students] …
GMAT Strategy Guide [Future Black MD MBA Students]
A + B - both + neither =total
A + B + C - [number in exactly two] - 2[number in exactly three] + none = total
Translate the scenario given into math by first determining what is the equivalency. What can I set equal to what. Using logic and solving in this systematic way equips you for nearly any word problem. You don't need to know esoteric math rule most of the time.
Distance Rate Problems
Determine what is the equivalency. Usually the equivalency is two distances
Other Rate Problems
Remember that with all other rate problems determine what the denominator of the rate is and you know automatically when setting up an equivalency/formula this rate must be multiplied by the units of whatever is in the denominator then go from there to piece together an equation.
Combined Work Problems (x machines/persons doing the SAME job)
a(1/A) + b(1/B) = 1/T
a(1/A) + b(1/B) + c(1/C) = 1/T
Probability/Combinatorics/Permutations (harder level problems will make these harder by combining more than one type a common combination is a probability problem where the numerator and the denominator can be found individually by doing a combinatorics calculation)
Combinatorics Problems --- this is distinguished from permutations because the key words for these problems is typically "how many ways" of doing a thing whereas permutations deals with the specific ordering of doing a thing.
Permutation Problems --- this is distinguished from combinatorics problems because it accounts for the specific ordering of given scenarios
The round table --- the first person of 5 people who sits has essentially 5 identical seats to choose from so the permutation goes 1 x 4x 3 x 2 x 1
The square table --- the first person of 5 who sits has essentially has 2 sets of identical seats to choose from [a corner seats to the left of a corner and a corner seat to the right of a corner and the permutation becomes
Probability --- for rate problems we saw that determining what is the denominator first helps and the same is true for probability problems. think about and determine what will be in the denominator
For a subset of probability problems it is much easier to compute 1-p than it is to calculate p. An example is if a problem ask you to calculate the amount for at most11 of 13 scenarios. Instead of calculating the probability of less or equal to 11 it is easier to do 13 - (probability of the 12th and 13th instance).
Critical Reasoning Section
Read to Understand the Argument (it may be helpful to write and draw arrows establishing relationships between key parts of the argument but do this in shorthand to save time)