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32 votes
32 votes
In Bloomington, the use of landlines has been declining at a rate of 19% every year. If there are 74,356 landlines this year, how many will there be in 11 years?If necessary, round your answer to the nearest whole number.

User Janneck Lange
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1 Answer

18 votes
18 votes

Solution

- The rate formula we shall use for this question is given below:


\begin{gathered} A=P(1-r)^t \\ \text{where,} \\ P=\text{Initial number of landlines} \\ r=\text{decline rate per year} \\ t=\text{ number of years} \end{gathered}

- The parameters have been given to us and are listed below


\begin{gathered} P=74356 \\ r=19\text{ \%}=0.19 \\ t=11 \end{gathered}

- Thus, we can simply proceed to find the Amount (A) of landlines in use in the next 11 years as follows


\begin{gathered} A=74356(1-0.19)^(11) \\ \\ A=74356(0.81)^(11) \\ \\ \therefore A=7322.3625\ldots\approx7322\text{ (To the nearest whole number)} \end{gathered}

Final Answer

The answer is

There will be only 7322 landlines in the next 11 years

User Jeff Atwood
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