Consider the question. 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 $350, how many students can go on the field trip?
 If the answer is '25'; explain the reasoning:
There is $350 - $100 = $250 available to pay for the students' admission fees. This means they can afford to bring $250 / $10 = 25 students on the trip.