$\"\"$

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The exponential decay function is $\"\"$ .

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The initial amount of salt is $\"\"$ .

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The amount of salt left after $\"\"$ hours is $\"\"$ .

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Hence, $\"\"$ and $\"\"$ .

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Substitute all the values in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Therefore,the decay constant is $\"\"$

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$\"\"$

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The equation is $\"\"$ .

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Find the amount of salt will remain after one day.

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Substitute $\"\"$ and $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Therefore,the amount of salt is reaches $\"\"$ after one day..

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$\"\"$

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Fid the time to reach salt $\"\"$ .

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

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$\"\"$

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$\"\"$

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$\"\"$

\

$\"\"$

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Therefore, the amount of salt reaches $\"\"$ after $\"\"$ .

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$\"\"$

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The amount of salt is reaches $\"\"$ after one day.

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The amount of salt reaches $\"\"$ after $\"\"$ .