GMAT Quant Chapter 3: Properties of Numbers Flashcards
For the GMAT, is 0 considered to be positive or negative?
Neither.
The GMAT does not consider 0 to be positive or negative.
What is the square root of 0?
Is 0 even or odd?
0 is the only number that …?
0
Even
is equal to its opposite.
What is the number with only 1 factor?
What is the first prime number?
2.
What do even exponents always produce?
Positive results.
How can we determine all the factors of a number?
Start at 1 and list all of the factors.
What are the first 25 prime numbers?
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47
53
59
61
67
71
73
79
83
89
97
Define a composite number.
How can we express the factors of this type of number?
Any number that is not prime.
As a product of its prime factors.
How do we find the number of factors for a given number?
Step I. Prime Factorize
Step II. +1 to the value of each exponent of the PFs.
Step III. Multiply all of the (PFs +1) together
What is the difference between a unique prime factor and a prime factor?
A unique prime factor is the only prime factor for a given number.
A prime factor is any number that is only divisible by 1 and itself.
How do we calculate the Lowest Common Multiple (LCM) of two numbers?
- Prime Factorize each integer
- If any PFs are repeated, take only the largest exponent
- Take all non-repeated PFs
- Multiply the values from Steps 2 & 3
How do we find the LCM for more than 2 integers?
- PF
- Find repeated PFs with highest exponent (PF shared by at least 2 numbers)
- Take all non-repeated PFs
- Multiply steps 2 & 3 values
How do we calculate the LCM if two integers do not share PFs?
Multiply the integers together.
How do we find the Greatest Common Factor (GCF)?
- PF each number
- Find repeated PFs
- take smallest exponents of repeated PFs
- Multiply numbers from step 3
How do we calculate the GCF if there are no repeated PFs?
take only those with the smallest exponent
What is the GCF if a set of integers has no prime factors?
1.
If we have two integers x and y, and we know the LCM of one and the GCF of another, what can we calculate?
LCM x GCF of two seperate integers = the product of those two integers.