Seniors in a student council of a high school are trying to come up with a budget for the Senior Ball. Here is some information they have gathered: -Last year, 120 people attended. It was a success and is expected to be even bigger this year. Anywhere up to 200 people might attend.

-There needs to be at least 1 chaperone for every 20 students.

-The ticket price can not exceed $20 per person.

-The revenue from ticket sales needs to cover the cost of the meals and entertainment, and also make a profit of at least $200 to be contributed to the school.

Kiran says we should add the constraint t ≥ 0

1. What is the reasoning behind this constraint?

2. What other "natural constraint" like this should be added?