Pipe A can fill a tank in 2 hours, pipe B in 4 hours and pipe C in 4 hours. If all the pipes are open, in how many hours will the tank be filled? Choose the correct choice from the following choices: A) 2 B) 1 C) 3 D) 4 E) 5
Answer:	Part filled by A + B + C in 1 hour = 1/2 + 1/4 + 1/4= 
<gadget id="calculator">1/2 + 1/4 + 1/4</gadget>
<output>1</output>
1/1   All the three pipes together will fill the tank in 1 hours.   Answer: 1
<result>B</result>
Pipe A can fill a tank in 2 hours, pipe B in 4 hours and pipe C in 4 hours. If all the pipes are open, in how many hours will the tank be filled?