A thermometer reading `80^@F` is taken outside. Five minutes later the thermometer reads `60^@F` . After another 5 minutes the thermometer reads `50^@F` . What is the temperature outside?

Explanation

To solve the problem using Newton's Law of Cooling, we will follow these steps:

### Step 1: Set Up the Equation
According to Newton's Law of Cooling, the rate of change of temperature of an object is proportional to the difference between its temperature and the ambient temperature. We can express this as:

\[ \frac{dT}{dt} = -\lambda (T - S) \]
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