# Question: outcome can i use exponential and power functions to...

###### Question details

*Outcome : **Can I use exponential and power functions to model real-world contexts?*

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1. Before kerosene can be used as jet fuel it must have some pollutants in ti removed by passing it through clay. Experiments have shown when the clay is in a pipe each metre of pipe removes 20% of the pollutants that enter it. Write a formula for the amount of pollutants left in the fuel (in parts per million) as a function of the number of metres of the pipe the fuel has passed through. Assume that the initial amount of the pollutants in the kerosene is some value *P _{0}* (parts per million).

*** If it is possible, please explain this question very well (step by step explanation would be great). It's for university and I have never done maths like this before ***