A chemical plant has four tanks $\text{(A, B, C and D),}$ each containing $1000$ litres of a chemical. The chemical is being pumped from one tank to another as follows:
From $\text{A to B}\; @20$ litres/minute
From $\text{C to A}\; @ 90$ litres / minute
From $\text{A to D}\; @ 10$ litres / minute
From $\text{C to D}\; @ 50$ litres / minute
From $\text{B to C}\; @ 100$ litres /minute
From $\text{D to B}\; @ 100$ litres / minute
Which tank gets emptied first and how long does it take (in minutes) to get empty after pumping starts?
- $\text{A} 16.66$
- $\text{C}, 20$
- $\text{D}, 20$
- $\text{D}, 25$