Question

The rate of decreasing the temperature in a refrigerator is 3°C per minute. A thing whose temperature is 25°C, is kept in refrigerator. After how much time, the temperature of thing will be – 2°C?

Answer 1

Temperature of thing = 25°C

Rate of decreasing of temperature = -3°C per minute

Total decrease in temperature of thing after decreasing

from 25°C to – 2°C = (- 2) – 25

= -2 – 25

= – 27°C

Time taken to reach upto – 27°C at the rate of 3°C per minute = 27°C x 1/3°C per minute

= 9 minutes.