Pipe A can fill a tank in 4 hours, pipe B in 8 hours, and pipe C in 24 hours. If all the pipes are open, in how many hours will the tank be filled?
Choose the correct answer: A) 2.4 hours B) 2.8 hours C) 3.2 hours D) 4.8 hours E) 5.2 hours
The part filled by A + B + C in 1 hour   = 1/4 + 1/8 + 1/24   = 10/24   All the three pipes together will fill the tank in 24/10= 
<gadget id="calculator">24/10</gadget>
<output>12/5 = around 2.4</output>
2.4 hours.   The answer is 2.4 hours.
<result>A</result>
Pipe A can fill a tank in 4 hours, pipe B in 8 hours, and pipe C in 24 hours. If all the pipes are open, in how many hours will the tank be filled?