Prove DeMorgan's Law and Counting Using Lists
Let A, B, and C be sets. Then
A - (B union C) = (A - B) intersection (A - C) and A - (B intersection C) = (A - B) union (A - C)
2. 1.) A U.S. Social Security number is a nine-digit number. The first digit(s) may be 0.
a.) How many SS numbers are available? 10^9
b.) How many of these are even?
c.) How many have all of their digits even? 5^9
d.) How many read the same backward and forward?
e.) How many have none of their digits equal to 8? 9^9
f.) How many have at least one digit equal to 8?
g.) How many have exactly one 8?