Answer:
There must attend at least 80 adults to raise at least $1,000.
Explanation:
Givens
- Tickets are $3 for students and $5 for adults.
- They want to raise at least $1,000. (Restriction).
- 200 students attended.
Let's call
students and
adults.
We know the benefits are restricted as

Because, they want to raise AT LEAST $1000, that's the minimum amount possible.
Now, we know that
, replacing this value and solving for adults, we have

Therefore, there must attend at least 80 adults to raise at least $1,000.