A water tank is two-fifth full. Pipe A can fill a tank in 10 minutes and pipe B can empty it in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?
A. 6 min. to empty
B. 6 min. to full
C. 9 min. to empty
D. 9 min. to full
Answer:A
A water tank is two-fifth full. Pipe A can fill a tank in 10 minutes and pipe B can empty it in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?
A. 6 min. to empty B. 6 min. to full C. 9 min. to empty D. 9 min. to full