Pipes A and B fill a tank in 12 and 18 hours. Together they fill in:
Q1. Pipes A and B fill a tank in 12 and 18 hours. Together they fill in:
Answer: 7.2 hours
Explanation: Together rate is 1/12 plus 1/18, which is 5/36. Time is 36/5, which is 7.2 hours.