Saved Bookmarks
| 1. |
a cistern can be filled by a tap in 7 hours and emptied by an outlet pipe in 9 hours. how many will it take to fill the cistern if both the tap and the pipe are opened together.. |
|
Answer» Answer: Let x hours be required to fill 7 hours to fill tap so volume FILLED in 1 hour =1/7th of total volume similarly PIPE in 1 hour empties =1/9 th of total volume therefore net filling of cistern in one hour=1/7 - 1/9=2/63 Therefore (2/63)×x=1( whole volume) x=63/2 hours |
|