The temperature is dropping throughout the day as a cold front comes in. In City A, the temperature is changing by -5°F per hour, and in City B the temperature is changing by 3°F per hour. If the temperatures in both cities started at 70°F, which city is warmer, and what is the difference in their temperatures after 5 hours?

To determine which city is warmer and the difference in their temperatures after 5 hours, we can calculate the temperatures in both City A and City B after that time period.

City A:

• Initial temperature = 70°F
• Temperature change = -5°F per hour
• Time = 5 hours

Temperature after 5 hours in City A: \[ \text{Temperature in City A} = 70°F + (-5°F \times 5) = 70°F - 25°F = 45°F \]

City B:

• Initial temperature = 70°F
• Temperature change = 3°F per hour
• Time = 5 hours

Temperature after 5 hours in City B: \[ \text{Temperature in City B} = 70°F + (3°F \times 5) = 70°F + 15°F = 85°F \]

Now, we can compare the temperatures:

• Temperature in City A after 5 hours = 45°F
• Temperature in City B after 5 hours = 85°F

Now, let's determine which city is warmer and the difference in their temperatures:

• City B is warmer.
• The difference in temperatures = Temperature in City B - Temperature in City A: \[ \text{Difference} = 85°F - 45°F = 40°F \]

Conclusion: City B is warmer, and the difference in their temperatures after 5 hours is 40°F.

After 5 hours, City A's temperature drops to 45°F (from 70°F) because it cools at -5°F per hour. City B's temperature rises to 85°F (from 70°F) because it warms up at 3°F per hour. So, City B is warmer by 40°F.