Question

The temperature of a place at 6 p.m. is 12°C above zero. If it decreases at the rate of 2°C per hour
till 6 a.m., the next day, at what time would the temperature be 2°C below zero? What will be the
temperature at 6 a.m.?​

Answer 1

Answer: Every hour temperature decrease by 2\degree C2°C

Therefore the temperature decrease 2\degree C2°C = 1 hour

So the temperature decrease 1\degree C1°C = \frac{1}{2}\ hour  

2

1

​  

 hour

So the temperature at 18\degree C18°C = \frac{1}{2}\times18\ \ =\ 9\ hours\  

2

1

​  

×18  = 9 hours  

Total time = 12 hours + 9 hours

= 21 hours

= 9 pm

thus, at 9pm the temperature would be 8\degree C\ below\ 0\degree C8°C below 0°C