Final answer:
The temperature on Boxing Day was 3°C after dropping to -10°C on Christmas Day and warming up by 13°C.
Step-by-step explanation:
On Christmas Day, the temperature dropped 2°C from -8°C, resulting in a temperature of -10°C. Then, on Boxing Day, it warmed up by 13°C. Adding this increase to the Christmas Day temperature, we get -10°C + 13°C = 3°C. Therefore, on Boxing Day, the temperature was 3°C. The initial decrease on Christmas Day and subsequent increase on Boxing Day collectively contribute to a net change of +11°C from the original temperature on Christmas Eve. We start at -10°C and add 13°C to find the temperature on Boxing Day: -10°C + 13°C = 3°C, Therefore, it was 3°C on Boxing Day.