# Week 1 Flashcards

What is N?

Natural Numbers, non-negative number

What is Z?

Set of all integers

What is Z+?

Set of all positive integers

What is Q?

Set of all rational numbers

What is R?

Set of all real numbers

What is R+?

Set of all positive real numbers

What is C?

Set of all complex numbers

What is the size of the Power Set?

|P(s)| = 2^n

Are the following pairwise different?

(1, 2, 3) , (1, 3, 2), (2, 1, 3), (3, 1, 2)

Yes

if |A| = a and |B| = b, what is the size of A x B?

ab

if |A| = a, what is the size of A^n?

a^n

Let A be any set. What is the size of A x 0?

0

How many different license plates are available if each plate contains a sequence of 3 letters followed by 3 digits?

26^3 * 10^3 choices

How many subsets does the set S = {1, …, n} have?

2^n

FORMULA FOR INCLUSIVE-EXCUSLIVE PRINCIPLE OF 2 SETS

|A∪B| = |A| + |B| - |A∩B|