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If an initial quantity $\"\"$ grove or decays at an exponential rate $\"\"$ or $\"\"$ , then the final amount $\"\"$ after a time $\"\"$ is given by the following formula $\"\"$ .

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(a)

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Find exponential equation for $\"\"$ .

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Growth rate of inflation between $\"\"$ and $\"\"$ .

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So the time period is $\"\"$ .

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CPI in $\"\"$ was $\"\"$ and $\"\"$ was $\"\"$ .

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Substitute $\"\"$ , $\"\"$ and $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$ .

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Exponential equation is $\"\"$ .

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(b)

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Find the CPI in $\"\"$ .

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Growth rate of inflation between $\"\"$ and $\"\"$ .

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So the time period is $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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Find when CPI exceeds 350.

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$\"\"$

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Apply logarithm on each side.

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$\"\"$

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$\"\"$ .

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CPI exceeds after $\"\"$ years, so CPI exceeds after $\"\"$ .

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(a) Exponential equation is $\"\"$ .

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(b)

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CPI in $\"\"$ is $\"\"$ .

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CPI exceeds after $\"\"$ years.