The Marching Band is traveling from Minnesota to Florida to perform in a national competition. A train ticket from Minnesota to Florida costs $150 and takes 15 hours of travel time per student. To rent a bus to make the trip, it costs $120 per student and takes 20 hours of travel time per student. The band has $4,800 to spend on the trip and can only spend 720 hours of total travel time. Use the information below.

Let x = Students traveling by train
Let y = Students traveling by bus

Therefore,
$150x + $120y < $4,800 and
15x + 20y < 720.

The graph of these functions is to the right.

It is impossible for a negative number of students to go on the trip, so x and y both have to be greater than zero. Therefore, the functions are confined to the first quadrant.

Number of students function:
N = x + y