The cost to rent a school bus is $100.
The cost of admission is $10 per student.
The teacher is allowed in for free.
Let's represent the number of students as s.
The total cost of the field trip is the sum of the cost of the bus and the cost of admission for the students: $100 + $10s.
We are given that the total cost is x, so we can write: $100 + $10s = x.
Solving for s, we get: s = (x - $100)/$10.
We are given that the number of students is 25, so we can write: (x - $100)/$10 = 25.
Multiplying both sides by $10, we get: x - $100 = $250.
Adding $100 to both sides, we get: x = $350.
The value of x is $350.
#### 350
The answer is: 350
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
The class plans to take a field trip to the zoo. The cost to rent a school bus is $100. The cost of admission is $10 per student. The teacher is allowed in for free. If the class has a budget of x, how many students can go on the field trip?
If we know the answer to the above question is 25, what is the value of unknown variable x?

### Answer:
