Question

The temperature at 12 noon was 10°C above zero. If it decreases at the rate of 2° per hours until midnight, at what time would the temperature be 8°C below zero. What would be the temperature at mid night?​

Answer 1

Temperature at 12 Noon = 10°C above 0°C = 10°C

   It decreases at 2° per hour.

Final temperature = 8°C below 0 = -8°C

Change in temperature = 10 - ( -8 ) = 18°C.

Rate of decrease = 2° per hour.

Time = 18 / 2 = 9 hours

So, Time at which temperature would be 8°C below zero = 12:00 + 9:00 = 21:00

So, the time at which temperature goes 8°C below 0 is 9:00 PM.

Also, The temperature at 12 :00 PM = 10° C, As temperature decreases at 2°C,

Temperature at mid night = 10° C - 2 ( 12 ) = 10 - 24 = -14° C.