Question

M = {x : x is a natural number between 0 and 8) and N = {x : x is a natural number from 5 to 10}. Find: M – N and n(M – N)

Answer 1

Set M: Natural numbers between 0 and 8 (excluding 0, as natural numbers start from 1):

M = {1, 2, 3, 4, 5, 6, 7, 8}.

Set N: Natural numbers from 5 to 10:

N = {5, 6, 7, 8, 9, 10}.

The set difference M − N is defined as the elements of M that are not in N

Elements of M: {1, 2, 3, 4, 5, 6, 7, 8}.

Remove elements that are also in N: {5, 6, 7, 8}.

M − N = {1, 2, 3, 4}.

The number of elements in M − N is the count of elements in {1, 2, 3, 4}

n(M − N) =  4

1. M − N = {1, 2, 3, 4}
2. n(M − N) = 4