SOLUTION: Pipe A can fill a tank in 3 hours. If pipe B can fill the same tank in 2 hours, how many minutes will it take both pipes to fill 2/3 of the tank?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Pipe A can fill a tank in 3 hours. If pipe B can fill the same tank in 2 hours, how many minutes will it take both pipes to fill 2/3 of the tank?      Log On


   

Question 751260: Pipe A can fill a tank in 3 hours. If pipe B can fill the same tank in 2 hours, how many minutes will it take both pipes to fill 2/3 of the tank?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +t+ = time in hrs for both pipes
to fill +2%2F3+ of the tank
Add their rates of filling to get rate filling together
( 1 tank filled / 3 hrs ) + ( 1 tank filled / 2 hrs ) = ( 2/3 tank / t hrs )
+1%2F3+%2B+1%2F2+=+%28%282%2F3%29+%2F+t%29+
Multiply both sides by +6t+
+2t+%2B+3t+=+6%2A%282%2F3%29+
+5t+=+12%2F3+
+5t+=+4+
+t+=+4%2F5+
+%284%2F5%29%2A60+=+48+
It will take 48 minutes for
both pipes to fill 2/3 of the tank
check:
+1%2F3+%2B+1%2F2+=+%28%282%2F3%29+%2F+t%29+
+1%2F3+%2B+1%2F2+=+%282%2F3%29+%2F+%284%2F5%29+
+1%2F3+%2B+1%2F2+=+%282%2F3%29%2A%285%2F4%29+
+1%2F3+%2B+1%2F2+=+5%2F6+
Multiply both sides by +6+
+2+%2B+3+=+5+
OK