Answer:
16 °C
Explanation:
We are told that Ken predicts that, in August, the average low temperature will be 20°C, and that the temperature will drop by 4°C in September.
Now, in a standard 12 month calendar, the month of August comes before the month of September.
Thus, in September a drop off by 4°C from 20°C means that the new temperature in September is; 20°C - 4°C = 16 °C