Final answer:
Using the principle of Inclusion-Exclusion, the number of people not reading either newspaper X or Y is calculated to be 3,000, which is option (b).
Step-by-step explanation:
The student's question is about finding the number of people who do not read either of the two newspapers, X and Y, out of a total town population of 50,000 people. Given that 28,000 read newspaper X, 23,000 read newspaper Y, and 4,000 read both newspapers, we can use the principle of Inclusion-Exclusion to solve this problem.
To calculate the number of people who read at least one of the newspapers, we sum the readers of newspapers X and Y and then subtract the number of people who read both, to avoid double-counting:
Number of people reading at least one paper = (Readers of X) + (Readers of Y) - (Readers of both X and Y)
= 28,000 + 23,000 - 4,000
= 47,000.
Since the total population is 50,000, by subtracting the readers of at least one paper from the total population, we get the number of people not reading either newspaper:
Number of people not reading either paper = Total population - Number of people reading at least one paper
= 50,000 - 47,000
= 3,000.
Therefore, the number of persons not reading either X or Y is 3,000, which corresponds to option (b).