SOLUTION: One printing press can produce a newspaper in six hours running alone. . A second press can produce the paper and nine hours running alone a third press can produce the paper in ni

Algebra ->  Graphs -> SOLUTION: One printing press can produce a newspaper in six hours running alone. . A second press can produce the paper and nine hours running alone a third press can produce the paper in ni      Log On


   



Question 1024963: One printing press can produce a newspaper in six hours running alone. . A second press can produce the paper and nine hours running alone a third press can produce the paper in nine hours running alone. A third press could produce the paper in 12 hours working alone. A late breaking headline cause the newspaper to change the paper later than usual. If all three presses are running , How long will it take to produce the newspaper
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add the different rates of printing
to get their rate printing together.
Let +t+ = time in hours to
produce paper
+1%2F6+%2B+1%2F9+%2B+1%2F12+=+1%2Ft+
Multiply both sides by +36t+
+6t+%2B+4t+%2B+3t+=+36+
+13t+=+36+
+t+=+2+%2B+10%2F36+
Convert the fraction to minutes
+%28+10%2F36+%29%2A60+=+600%2F36+
+600%2F36+=+16+%2B+2%2F3+ min
Convert the fraction to seconds
+%28+2%2F3+%29%2A60+=+40+ sec
--------------------------
Working together, the presses take
2 hrs 16 min 40 sec
--------------------
check:
+1%2F6+%2B+1%2F9+%2B+1%2F12+=+1%2F2.7692+
+.1667+%2B+.1111+%2B+.0833+=+.3611+
+.3611+=+.3611+
OK