A bucket full of water is kept in a room and it colls from 75°C to 70°C in time T, minutes, from 70°C to 65°C in time T2 minutes, and from 65°C to 60°C in time T3 minutes, then

According to Newton's Law of Cooling, the rate of heat loss from a body is directly proportional to the temperature difference between the body and its surroundings. Mathematically, as the temperature of the bucket of water decreases and approaches the ambient room temperature, the temperature gradient (difference) becomes smaller. Since the rate of cooling is proportional to this difference, the water cools more slowly as it gets closer to room temperature. Consequently, for equal intervals of temperature drop (5°C in each case), the time required will increase as the average temperature of the water decreases. Therefore, the time T1 (75°C to 70°C) will be the shortest, followed by T2 (70°C to 65°C), and T3 (65°C to 60°C) will be the longest, leading to the relationship T1 < T2 < T3.