whats the cardinal number for 101, 102, 103, 104, . . . 128 and 101, 103, 105, . . . 251
The number of distinct elements in a finite set is called its cardinal number.
It is denoted as n(A) and read as ‘the number of elements of the set’.
For example:
(i) Set A = {2, 4, 5, 9, 15} has 5 elements.
Therefore, the cardinal number of set A = 5. So, it is denoted as n(A) = 5.
Set A = { 101, 102, 103, 104, . . . 128 }
subtract from each element 100 we have 1, 2, 3, ... , 28
n(A) = 128-100 = 28
Set B = { 101, 103, 105, . . . 251 }
subtract from each element 100 we have 1, 3, 5, ... , 151
151 = 2n-1
so \(n = \frac{150}{2} = 75\)
n(B) = 75