When considering a question that would be statistical, this would then let us know and understand that the question would then consists of math dealings with stocking such as business and status, and data that would contain interpretation, and etc. Sense you have not provided the questions, I hope this explanation helped narrow down some options!
If Sam buys 14 water bottles, he will have spent 18.9, so when you subtract 20 (the limit) from 18.9 (how much money he'll spend on the water bottles) you get 1.1