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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
by
3.4k points

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
by
3.1k points
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