Pipes A and B can fill a tank in 36 minutes and 45 minutes, respectively. Both these pipes were opened simultaneously. After 20 minutes, a leak at the bottom of the tank was spotted which was immediately sealed. The tank was full in another 15 minutes. The leak alone can empty the full tank in:
1
25 minutes
2
30 minutes
3
\(28\frac{1}{3}\) minutes
4
\(26\frac{2}{3}\) minutes