Final answer:
The temperature at 7:00 a.m. was 67° after subtracting the cooler temperature of 20° from the 1:00 p.m. temperature of 67°. Option C is correct.
Step-by-step explanation:
To find the temperature at 7:00 a.m., we need to subtract the cooler temperature from the temperature at 1:00 p.m. At 1:00 p.m., the temperature was 87°. It was stated that six hours earlier, the temperature was 20° cooler. Therefore, we would calculate the morning temperature by subtracting 20° from 87°.
87° - 20° = 67°
The temperature at 7:00 a.m. was therefore 67°. Answer C, 67°, is the correct choice.
To find the temperature at 7:00 a.m., we need to subtract 6 hours from 1:00 p.m. which gives us 7:00 a.m. Since the temperature was 20° cooler six hours earlier, we subtract 20 from 87° to find the temperature at 7:00 a.m.:
87° - 20° = 67°