GRE Math Flashcards
WIN
How many factors does 12 have?
12! (1,-1,2,-2,3,-3,4,-4,5,-5,6,-6,12,-12)
The product of an even integer and an odd integer is…
an even integer!
What digits can a prime number end in? How does this help to remember prime numbers below 100?
1,3,7 or 9 (expect for the only even prime 2). You then only need to double check if the number is divisible by 3 (if the number sum is divisible by 3) or by 7- if not, it’s prime!
Is 1 a prime number?
No! (It’s also not composite)
How many even prime numbers are there?
The only even prime number is 2!
What is a positive number that is not prime?
Composite!
What is the relationship between prime and composite numbers?
All composite numbers can be uniquely expressed as a product of factors that are prime numbers/divisors - this expression is called prime factorization
When is 1 a factor or multiple?
1 is a factor of every integer, 1 is only a multiple of 1 and -1
What is 6 divided by 24 in terms of quotient and remainder?
0 remainder 6
What is -32 divided by 3 in terms of quotient and remainder?
-11 remainder 1 (remainders can be negative but it’s not in this case)
For odd ordered roots (like cubed root) how many roots are there for positive and negative numbers?
One root!
For even ordered roots (like square root) how many roots are there for positive and negative numbers?
Two roots for every positive number and no roots for any negative number!
what is 7,532.418 written as exponents of 10?
7(10^3)+5(10^2)+3(10)+2(10^0)+4(10^-1)+1(10^-2)+8(10^-3)
Are (-3^2) and -3^2 the same?
No! The first is +9 and the second is -9!
What is a^0 and 0^0?
a^0=1 and 0^0 is undefined
What is the square root of a) 0 and b) 16? How about wit the square root symbol?
a) 0, b) 4 and -4! With the square root symbol the answer is only the positive root.
√3√10 equals?
√30
√5/√15 equals?
√5/15 = √1/3
What’s the difference in terminology between a repeating and non-repeating decimal?
repeating=rational and non-repeating= irrational
Is the entire real number line an interval?
Yes!
What is (7√2)√2?
7(√2√2) = (7)(2)= 14
What is the triangle inequality?
|r+s| is less than or equal to |r| + |s|
If s is between 0 and 1, how does s^2 compare to s?
s^2 is LESS than s!
What is the base when computing percent increase and decrease?
increase = base is smaller number, decrease = base is larger number!