Let us say that you have a restaurant and you want to increase the frequency of visits of customers who have lunch only few times a month.
A fixed meal costs $20 and there are varieties.
Average visits 5 times a month
Each customer pays on average $100 a month
You would like to make a proposal so that they would have lunch at least 20 times a month, for this you are prepared to lower the price of the meal from $20 to $x
The actual cost of a meal is $5 and you would like to have at least $3 profit, so we can add the condition x>8, but that would really be bad for business.
What is the optimal x in your opinion for the customers and the restaurant owner? Please try to be fair as a customer and also as the owner.
This is not a mathematical puzzle. The answer would be based mainly on common sense and some knowledge about business.
If you can think of a better proposal, please let's hear it.