Final answer:
The price of one slice of pizza that Noah is selling at the school event is $1.25.
Step-by-step explanation:
The question is asking for the price of one slice of pizza that Noah is selling during a school event. The given price is $1.25 per slice. Therefore, the correct answer is option 2) $1.25. This is a straightforward arithmetic problem that does not require the use of a demand equation or any other complex calculations.