Pipe A can fill a tank in 8 hours, pipe B in 16 hours and pipe C in 48 hours. If all the pipes are open,in how many hours will the tank be filled ?	Choose the most appropriate option
A) 4.7 B) 4.5 C) 4.6 D) 4.8 E) 5
1/8+1/16+1/48=10/48=1/4.8. so 4.8 hrs   ANSWER:4.8
<result>D</result>
Pipe A can fill a tank in 8 hours, pipe B in 16 hours and pipe C in 48 hours. If all the pipes are open,in how many hours will the tank be filled ?