Hot water cools from 60^@Cto50^@C in the first 10 minute and to 42^@C in the next 10 minutes.Then,the tempreature of the surroundings is

Hot water cools from 60^@Cto50^@C in the first 10 minute and to 42^@C

1.	Hot water cools from 60^@Cto50^@C in the first 10 minute and to 42^@C in the next 10 minutes.Then,the tempreature of the surroundings is
Answer» `20^@C` `30^@C` `15^@C` `10^@C` ANSWER :D