Prove DeMorgan's Laws for sets?

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)

Counting problems using lists?
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?
b.) How many of these are even?
c.) How many have all of their digits even?
d.) How many read the same backward and forward?
e.) How many have none of their digits equal to 8?
f.) How many have at least one digit equal to 8?
g.) How many have exactly one 8?

1 answer

u is equal n koma b is equal p a is equal phie