The temperature of a town at 3p.m. was `21^(@)C`. Every hour it decreases by `3^(@)C`. What will be the temperature at 6 p.m.?

Options

A. `3^(@)C`
B. `0^(@)C`
C. `12^(@)C`
D. `-6^(@)C`

Answer

To find the temperature at 6 p.m., we can follow these steps:

### Step 1: Identify the initial temperature and the time interval
- The initial temperature at 3 p.m. is `21°C`.
- We need to find the temperature at 6 p.m., which is 3 hours later.

### Step 2: Determine the temperature decrease per hour
- The temperature decreases by `3°C` every hour.

### Step 3: Calculate the total decrease in temperature over 3 hours
- Since the temperature decreases by `3°C` each hour, over 3 hours, the total decrease will be:
\[ \text{Total decrease} = \text{Decrease per hour} \times \text{Number of hours} = 3°C \times 3 = 9°C \]

### Step 4: Calculate the temperature at 6 p.m.
- To find the temperature at 6 p.m., we subtract the total decrease from the initial temperature:
\[ \text{Temperature at 6 p.m.} = \text{Initial temperature} - \text{Total decrease} = 21°C - 9°C = 12°C \]

### Final Answer:
- The temperature at 6 p.m. will be `12°C`.

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