Your question is Booking Experiences Optimization. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You have a variable number of hours during a layover in Paris and want to book experiences on Airbnb; you prefer to book as few experiences as possible while using all available hours, and if no combination allows you to use all hours, you choose not to book any experiences.