Answer:
n(T) = 7
Explanation:
Given the set T{X: 2<x ≤ 9} where x is an integer, the element of the set T will be {3, 4, 5, 6, 7, 8, 9}. note that from the inequality set 2<x ≤ 9, x is not equal to 2 but greater than 2. The inequality can be divided into two as shown;
If 2<x ≤ 9 then 2<x and x≤9
If 2<x, this means x>2 but not equal to 2. This is the reason why 2 is not contained in the set T.
Similarly if x≤9, this shows that x can not be greater than 9 but less than or equal to 9.
Since the set T = {3, 4, 5, 6, 7, 8, 9}, we are to find n(T). n(T) means cardinality of the set T and cardinality of a set is defined as the total number of element in a set.
Hence n()n(T) = 7 (since there are 7 elements in the set T)