What is the total number of students having specialisation in IR, marketing and IT?

Number of students in various specialisations:
$$\eqalign{ & \text{IB → } \frac{19}{100}\times8000 = 1520 \cr & \text{IR → } \frac{16}{100}\times8000 = 1280 \cr & \text{Finance → } \frac{12}{100}\times8000 = 960 \cr & \text{Marketing → } \frac{22}{100}\times8000 = 1760 \cr & \text{IT → } \frac{17}{100}\times8000 = 1360 \cr & \text{HR → } \frac{14}{100}\times8000 = 1120 \cr} $$

Required number of students
= 1280 + 1760 + 1360
= 4400