SOLUTION: One pipe alone can fill a tub in 12 minutes. Another pipe can fill it in only 8 minutes, how long will it take for both pipes to fill the tub if they work together?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: One pipe alone can fill a tub in 12 minutes. Another pipe can fill it in only 8 minutes, how long will it take for both pipes to fill the tub if they work together?      Log On


   

Question 770103: One pipe alone can fill a tub in 12 minutes. Another pipe can fill it in only 8 minutes, how long will it take for both pipes to fill the tub if they work together?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add their rates of filling
1st pipe's rate:
( 1 tub ) / ( 12 min )
2nd pipe's rate:
( 1 tub ) / ( 8 min )
----------------
Let +t+ = time in minutes for
both pipes to fill tub
+1%2F12+%2B+1%2F8+=+1%2Ft+
Multiply both sides by +24t+
+2t+%2B+3t+=+24+
+5t+=+24+
+t+=+4.8+
It will take them 4.8 min