SOLUTION: One tap can fill a cistern in 2 hours and another empty the cistern in 3 hours.How long will they take to fill the cistern if both the taps are opened ?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: One tap can fill a cistern in 2 hours and another empty the cistern in 3 hours.How long will they take to fill the cistern if both the taps are opened ?      Log On


   

Question 728854: One tap can fill a cistern in 2 hours and another empty the cistern in 3 hours.How long will they take to fill the cistern if both the taps are opened ?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add the rate of filling and
subtract the rate of emptying
( 1 cistern filled / 2 hrs ) minus ( 1 cistern emptied / 3 hrs ) = ( 1 cistern filled / t hrs )
+1%2F2+-+1%2F3+=+1%2Ft+
Multiply both sides by +6t+
+3t+-+2t+=+6+
+t+=+6+
It will take 6 hrs with both taps open