Quant Strategies Flashcards
Absolute value
Complex abs val where there’s multiple, like |4x-7| = |x-8|, what’s x?
”- Only need to solve for 2 scenarios, both are positive, any one is - /+; like x-2 = 2x-3, and x-2 = - (2x-3)
- DON’T FORGET TO PLUG BACK IN TO CHECK”
Backsolving
Follow the flow of the problem, plug in the choices
Careless Typo - don’t write J as 1
Slow down
Careless 9 and a in a problem
Squigly a and straight 9, be careful
Careless 19+7
26
Combo If you see the question asking for 2 variables, ie x/y =?
- Simplify question if you can
- Try to manipulate answer choices to solve the combo, not indiv var”
Combo If DS option is combo, ie x/y and the question asks what xy=?
TEST CASES: Instead of plugging it in, you can just say x could be 4, y could be 2
Combo You don’t need to solve if in DS, you have combo in stem
- if you can manipulate the choices to the same as the problem, or the 2 choices are actually the same - not C
DS Data Sufficiency
AD/BCE, BD/ACE
DS When you have a gnarly fraction, look at answer choices to try to manipulate it there, ie (2t+t-x) / (t-x)
”- Signal: 2t+t must be like that for a reason, don’t just go 3x
- 2t / (t-x) + 1 bc that’s in answers”
DS Don’t forget to test which number?
“1; practice starting with 1 unless it’s not allowed
- Helps you get faster with testing cases”
DS When you have equation in question
Don’t assume that it’s given, write out equation with “?” for each stem
Equations System of equations
”- Figure out what to solve for, x
- Isolate other variables, y (put y on 1 side, and rest on other side), plug into 2nd equation
- Practice both subsitution ^ or add/subtract equations (if it’s already laid out)”
Equations 2 variables in 1 equation
Can’t solve if you have 2 variables
Equations If the question has x and y, asks what y could be and gives you multiple choice, solve for…
Solve for y –> x = y something, that way, you can plug y into the equation
Equations If you have 2 equations, you can; ie xy=2, yz=3, xz=4
Multiple, add, subtract together; ie x^2y^2z^2=24
Equations If you have 3 equations where all variables don’t have coefficient,
Add the 3 together, then you can sub 1 equation with 2 variables at a time
Equations If problem asks for what the smallest possible value is, |37-5y|
”- Signal: 5y is a divisor, so you can think of 0, 5
- Other strategy is to test number”
Exponents Same exponent but different base in a fraction (no addition / subtraction in between)
“Consolidate the fraction and put it all over exponent
- if unsure, check if it works the other way”
Exponents Same base with exponent, if division, you can
If division, you can subtract exponents. If multiplication, you can add
Exponents Exponent to the exponent (2^3)^4
Multiple the exponents: 2^12
Exponents See exponential terms being added (11^3 + 11^2)
Can’t multiple exponents, try factoring out
.Exponents Fraction in exponent (8^(2/3)
“Can’t split fraction by multiplying it out with the same base; not 8^2*8^(1/3)
- Instead, simplify base and see if you can x or / exponents”
Exponents Memorize 4^n, ending unit pattern is
4, 6 | 4, 6