what is the cardinal number of the set {1, 3, 7, 4, 22, 16, 12}? Where denotes the set of all natural numbers.

Draw a "bag diagram" to illustrate the following set and find it cardinal number {{1,2}, {1,2,3}, {4}}

The natural numbers are N= 1,2,3,.. The prime numbers are P = 2,3,5,7.. True or false? The intersection of {1,2,3,4,5} with P is the set {1,2,3} True False

I am confused on how to actually find the cardinal number when given an infinite set.Find the cardinal number of each of the following sets. Assume the pattern of elements continues in each part in the order given.{ 201, 202, 203, ..., 1100}