At noon, the temperature was 5.4°C. By 4:00 pm, the temperature had dropped 12°C, and by 7:00 pm the temperature had dropped another 8.9°C. What was the temperature at 7:00 pm?
The correct answer and explanation is:
To determine the temperature at 7:00 pm, start by noting the initial temperature and the changes in temperature over time.
- At noon, the temperature was 5.4°C.
- By 4:00 pm, the temperature had dropped by 12°C. So, subtract 12°C from the initial temperature: 5.4°C−12°C=−6.6°C5.4°C – 12°C = -6.6°C Therefore, the temperature at 4:00 pm was -6.6°C.
- By 7:00 pm, the temperature had dropped another 8.9°C. So, subtract 8.9°C from the 4:00 pm temperature: −6.6°C−8.9°C=−15.5°C-6.6°C – 8.9°C = -15.5°C Therefore, the temperature at 7:00 pm was -15.5°C.
The correct temperature at 7:00 pm is -15.5°C.
Explanation:
To solve the problem, you need to follow the sequence of temperature changes. First, subtract the temperature drop between noon and 4:00 pm. Then, subtract the additional temperature drop between 4:00 pm and 7:00 pm. Each subtraction represents the drop in temperature over a given period.
This method involves basic addition and subtraction of temperature changes. The result is negative because the temperature is decreasing. The key is to keep track of each drop step by step, making sure to adjust the temperature properly at each stage.