A machine can filled a tank in 25 minutes and another machine can empty it in 50 minutes. If the tank is already half full and both the taps are opened together, then the tank is filled in how many minutes?
Select the correct option.
A) 25 min
B) 20 min
C) 10 min
D) 15 min
E) 30 min

Rationale: t = 1 / 2 ( 25 * 50 / 50 - 25 ) = 25 minutes tank is filled in 25 minutes answer is a
Answer: A