Of the 16 applicants, 10 are not present employees and 6 are present employees. 1 of the 10 non-employees is to be hired, meaning that 2 of the 6 employees are to be hired. If 1 of 10 non-employees are to be hired, that's 10 "groups" of 1 employee to choose from.

If 2 of 6 employees are to be hired, we need to use the combinations formula for a set of 6 and a desired subset of 2:
= 6! / (6 - 2)!(2)!
= 6! / 4!2!
= 6(5) / 2
= 15
To find the total number of 3-person groups that contain 2 present employees and one non-employee, multiply those two numbers of groups together:
(10)(15) = 150, choice (D).