Correct Answer - Option 2 : 45 minutes

**Given:**

Tap A can fill the tank in 12 minutes

The tap B can fill the tank in 15 minutes

The tap C can empty the tank in 6 minutes

**Calculation:**

⇒ One minutes work of A and B = (1/12 + 1/15) = 3/20

⇒ 5 minutes work of A and B = 5 × (3/20) = 3/4

⇒ The one minutes of work of A, B, and C = (1/12 + 1/15 - 1/6) = -1/60

⇒ Time taken when all three tap opened = (3/4) × (60) = 45 minutes

**∴ The required result will be 45 minutes.**