I would say that statistics is a mathematical subject that allows you to explain scientific data. In a similar fashion, you could use mathematics to explain the various idea in physics as you can use statistics to interpret the results of experiments and the data collected.
It would take the faucet 18 hours to fill the tank because 18/12=1.5. That means it will be 1.5 times slower to fill the tank up with the hose on. 1.5*12=18.
