A body cools from \(80^\circ\text{C}\) to \(50^\circ\text{C}\) in \(5\) minutes. The time it takes to cool from \(60^\circ\text{C}\) to \(30^\circ\text{C}\) is:
(The temperature of the surroundings is \(20^\circ\text{C}\))
1. \(13~\text{min}\) 
2. \(15~\text{min}\) 
3. \(12~\text{min}\) 
4. \(10~\text{min}\)