Wow. That is a nice tuition.
The question is asking, how much money does he need to pay after taking consideration of the grant money and scholarship.
We need to add up the estimated costs for his first year. 1,600+400+1,400=3,400.
Subtract both 1,900 and 1,000 (2,900) because he does not need to pay that amount from the original estimated costs.
3,400-2,900=500
This means that aside from the financial aid help, he will need to pay an additional 500 dollars to pay for his first year of college.