The mean temperature for the first 4 days in January was -6°C. The mean temperature for the first 5 days in January was -5°C. What was the temperature on the 5th day?
- 6 x 4 days ==- 24
- 5 x 5 days == - 25
- 25 - ( - 24) == - 1 - temperatue on the 5th day.
