Consider Luis's decision to go to college. If he goes to college, he will spend $21,000 on tuition, $11,000 on room and board, and $1,800 on books. If he does not go to college, he will earn $16,000 working in a store and spend $7,200 on room and board. Luis's cost of going to college is

$42,600

Explanation:

The computation of the cost of going to college is given below:

the total cost when he goes to college he spends

21,000 on tuition

11,000 on room and board

1,800 on books

So, the total should be $33,800

Now in the case when he does not go to college

So,  

he will earn 16,000 working in a store

and spend 7,200 on room and board

So, the saving amount should be

=  16,000 - 7,200

= $8,800

Now the cost should be  

= 33,800+8,800

= $42,600

there's 11 people for the 1st position. then, no matter who gets it, there's only 10 left for the second, and then 9 left for the third. 11 x 10 x 9 = 990.   the answer is there are 990 different ways the positions can be filled by these applicants