9514 1404 393
Answer:
5.8496 min
Step-by-step explanation:
[tex]\displaystyle t=\frac{10}{\ln{2}}\int_{220}^{280}{\frac{1}{T-100}}\,dT=\frac{10(\ln{(280-100)}-\ln{(220-100)})}{\ln{2}}=\frac{10\ln{(3/2)}}{\ln{2}}\\\\\boxed{t\approx5.8496\quad\text{min}}[/tex]
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Modern calculators can perform integration with high accuracy. This one gives the same result.
