Answer:
9 bottles of water
Step-by-step explanation:
Marginal benefit is a microeconomic concept that explains how much the consumer adds satisfaction to each unit consumed of a given product. Usually, the marginal benefit is decreasing, which makes logical sense, the more a customer consumes a particular good, the smaller the benefit of the next unit.
At first, the first bottle of water has a high benefit as mentioned in the exercise: 9
In the second, you are a little less thirsty, so the benefit will be 10 - 1x2 = $8
In the ninth bottle, you will have very little thirst and the benefit will be 10 - 1x9 = $1
In the tenth bottle there is no benefit, the consumer is indifferent. As a rational consumer, you will buy until the bottle is still usable, even if minimal, for 9 bottles when your benefit is $1.
