There are two taps, which are used to fill the tank and one tap to empty the tank. First tap fill the tank in 10 min., while the second takes quarter of an hour to fill the tank if both are operated independently.Third tap is capable of emptying the tank in seven and a half minutes. If all the taps are opened simultaneously how long (if ever) will it take for the tank to get filled completely?
Choose the correct choice from the following choices.
A) 10 minutes
B) 20 minutes
C) 30 minutes
D) 40 minutes
E) 50 minutes
Pipe A fills the tank in 10 min   Pipe B fills the tank in 15 min   Pipe 30 minutes empties the tank in 15/2 min   If all the three opened simultaneously then in 1 min   1/10 + 1/15 - 2/15 of the tank will be filled   that means 1/30 th of the tank will be filled in 1 min   So it will take 30 minutes to fill the tank completely if all three pipes opened   ANSWER:30 minutes
<result>C</result>
There are two taps, which are used to fill the tank and one tap to empty the tank. First tap fill the tank in 10 min., while the second takes quarter of an hour to fill the tank if both are operated independently.Third tap is capable of emptying the tank in seven and a half minutes. If all the taps are opened simultaneously how long (if ever) will it take for the tank to get filled completely?