The temperature at noon was 10°C above zero. If it decreases at the rate of 2°C per hour until mid-night, at what time would the temperature be 8°C below zero? What would be the temperature at mid-night?
Following number line is representing the temperature:
The temperature decreases 2oC = 1 hour
The temperature decreases 18oC = 1/2 x 18 =9 hours
Total time = 12 noon + 9 hours = 21 hours = 9 pm Thus, at 9 pm the temperature would be 8oC below 0oC.
