Question

A school invited 20 applicants for the role of subject teacher in physics and 15 applicants for mathematics. How many applicants came for the interview if 8 applicants applied for both subjects?

a. 27
b. 28
c. 29
d. 30

Answer 1

By applying the principle of inclusion and exclusion, the total number of distinct applicants who came for the interview is 27, after accounting for 8 applicants who applied for both physics and mathematics roles.

Step-by-step explanation:

To determine the number of applicants who came for the interview we can use the principle of inclusion and exclusion. According to the question, there are 20 applicants for the physics teacher role and 15 applicants for the mathematics teacher role. However, 8 applicants applied for both roles.

We add the number of applicants for each subject and subtract the applicants who applied for both to avoid double counting: 20 (physics) + 15 (mathematics) - 8 (both). So, the calculation would be 20 + 15 - 8 = 27.

Hence, the total number of distinct applicants for the interview is 27.