Answer
n(A) = 3
Work Step by Step
Given A={x|x is the letter in the word six}
From the given question.
Five is word which contains three Letters ‘S’,’I’,’X’
That is in the given set there are three letters.
The cardinal number for each set is formed by calculating the number of elements in each set.
Therefore the cardinal number for given set A is n(A) = 3.
