We wish to select 6 persons from 8, but if the person A is chosen, then B must be chosen. In how many ways can selections be made?

Solution:

It is known that,

As per the question,

Case 1:

If both the persons A and B are selected

Case 2:

If neither of the persons A nor B are selected

If the person B is selected but the person A is not selected

When we add the results of both persons A and B being selected, neither the person A or B being selected and the person B being selected but the person A not being selected,

We have,