Answer: -3.3°F
Explanation:
In integers , we represent fall in quantity by negative numbers.
Since, the temperature at noon was 16.8°F . By dropping it by 20.1°F means there is a - 20.1°F change in the temperature.
Then, the temperature at midnight = 16.8°F + (- 20.1°F)
= 16.8°F - 20.1°F
= -3.3°F
Hence, The temperature at midnight was -3.3°F .