Strategy Flashcards
Algebra vs. Arithmetic Strategy: Test Cases (TC)
DS: “Theory” problem. Use when the problem allows multiple possible values for the unknowns. Try at least two different cases to see whetehr you can get a different answers (Yes AND No; two DIFFERENT values)
PS: Use when the problem asks a “must be” or “could be” question. Test cases until only one answer choice remains
Algebra vs. Arithmetic Strategy: Choose Smart Numbers (SN)
PS Only.
When you see variable expressions or relative values (sich as percents, fractions, ratios) in the answers, check the problem to see whether you can use smart numbers.
If the problem never gives you a real number for that variable or relative value, you can use smart numbers.
Algebra vs. Arithmetic Strategy: Work Backwards (WB)
PS only.
Clues to work backwards:
- Pretty answer choices
- Questions asks for single value that you can plug in
B wrong + D wrong in opposite direction => C
B wrong + D wrong but getting better => E
Sufficiency of a Statement for a Value DS Problem
Sufficient: Provides exactly one possible value
Insufficient: Provides more than one possible value
Sufficiency of a Statement for a Yes/No DS Problem
Sufficient: Answer is Always Yes or Always No
Insufficient: Answer is Sometimes Yes, Sometimes No
Exponents in Test Cases Problem
Start with 0 and 1
Consider negatives
Consider fractions between 0 and 1 (or maybe between 0 and -1)
DS Guessing Strategies: “Identical Twins”
If both statements provide the exact same information, immediately cross off A, B, C
DS Guessing Strategies: “The Cannibal”
If statement 1 gets cannibalized, cross of A and C.
If statement 2 gets cannibalized, cross of B and C.
Of the 3 remaining answers, the best guess is the one associated with the cannibal (A or B) since that statement provides at least two pieces of relevant information.
DS Guessing Strategies: Suspecting a C Trap
If you suspect a C trap (i.e. it looks obvious that using the information together would be sufficient), then cross of C and E.
Then choose A or B depending on whether statement 1 or 2, respectively, look more complicated.
Primary Purpose Cheat Sheet
- Identify the question
Common language for Primary Purpose: primary purpose or function, author is primarily concerned with, author would be most likely to agree with
Common language for Paragraph: purpose of paragraph, relationship of paragraph to passage as a whole
- Find the spuport using map or general understanding of passage
- Predict an answer BEFORE looking at the answer choices
- Eliminate answers based on common traps (direct contradiction, extremes, one word off, out of scope, true but not right i.e. doesn’t answer the question)
Common Traps for Primary Purpos Questions
- Direct contradiction: the passage says the opposite
- Extremes: extreme language (“all” or “never”) without support in the passage
- One word off: tempting but 1-2 words are wrong
- Out of scope: goes beyond what the passage says
- True but not right: passage says it but it doesn’t answer the question
- Mix-up: uses words directly from the passage but the meaning is not what the passage says
When to estimate & things to keep in mind
If possible, try to make your rounding errors cancel out (i.e. round one number slightly up and the other number slightly down)
Estimate when:
- Problem explictely uses words like “approximate”
- Answer choices are far apart (in relative terms) or they cover certain “divided” characteristics
Divided characteristics:
- Positive vs. negative
- Fraction Problem: >1 vs. <1
- Probability Problem: >0.5 vs. <0.5
Specific Question Cheat Sheet
- Identify the question: detail (“according to the passage”); inference (“infer”, “imply”, “suggest”); specific purpose (“in order to”); EXCEPT
- Find the support. Find the specific paragraph of sentences needed or try to work backwards from the answers
- Predict an answer - formulate in your own words
- Eliminate and pick the right answer
More similar statements signify…
- The answer is less likely to be C or D
- The method to evaluate each statement will likely be the same
Data Sufficiency Framework
Across the top: Facts, Question (REPHRASE!), Type (Value or Yes/No), Elimination Grid (AD/BCE or BD/ACE)
Steps to solve a Sentence Correction question
- Write out A-E
- First Glance - scan for differences
- Read the “original” - ready for meaning and structure (core) and with my clues in mind
- Find an issue THAT I KNOW WHAT TO DO WITH
- Eliminate everything I can
Steps 3 and 4 are iterative until an answer is found
First step of a Problem Solving question
Look at the answers!
When to avoid algebra
Algebra is ugly if you have a system of nonlinear equations. You will end up with a quadratic if two unknowns get multiplied.
Common use cases to look out for:
- Area (base x height)
- Price x quantity