Hot water cools from `60^@C` to `50^@C` in the first 10 min and to `42^@C` in the next 10 min. The temperature of the surrounding is

Hot water cools from 60^@C to 50^@C in the first 10 minute and to 42^@C in the next 10 minute The temperature of the surrounding is

Hot water cools from 60^(@)C to 50^(@)C in the first 10 minutes and to 45^(@)C in the next 10 minutes. The temperature of the surroundings is:

Certain quantity of water cools from 70^@C to 60^@C in the first 5 minutes and to 54^@C in the next 5 minutes. The temperature of the surroundings is

Certain quantity of water,cools from 70^@C to 60^@C in the first 5 minutes! and to 54^@C in the next 5 minutes. The temperature of the surrounding is