$\"\"$

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The equation for cooling is $\"\"$ .

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The freezer kept at constant temperature $\"\"$ .

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The initial temperature of the liquid is $\"\"$ .

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Find the value of $\"\"$ .

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

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$\"\"$

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

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$\"\"$

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$\"\"$ .

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

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$\"\"$ .

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$\"\"$

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After five minutes the liquid temperature is $\"\"$ .

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

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$\"\"$

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Substitute $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Apply natural logarithm on each side.

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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

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$\"\"$ .

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$\"\"$

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Find the time taken to decrease the temperature to $\"\"$ .

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

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$\"\"$

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Already five minutes have passed, so the the time taken to decrease the temperature to $\"\"$ is

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$\"\"$ .

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$\"\"$

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Time taken to decrease the temperature to $\"\"$ is $\"\"$ .