A certain freezing process requires that room temperature be lowered from 40°C at the rate of 5°C every hour. What will be the room temperature 10 hours after the process begins?

Let us take the lowered temperature as negative.
Initial temperature = 40 degree Celsius
Change in temperature = -5 degree Celsius
Change in temperature after 10 hours = (-5)*10=-50 degree Celsius
Therefore, the final room temperature after 10 hours of freezing process = 40+(-50) = -10 degree Celsius.