SOLUTION: Show all pertinent solution: A student can do an encoding job for 10 minutes while another student can do the same job in 20 minutes. How long will it take them to finish the job

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Show all pertinent solution: A student can do an encoding job for 10 minutes while another student can do the same job in 20 minutes. How long will it take them to finish the job       Log On


   



Question 1039721: Show all pertinent solution:
A student can do an encoding job for 10 minutes while another student can do the same job in 20 minutes. How long will it take them to finish the job if they work together?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
1st student's rate of working:
( 1 job ) / ( 10 min )
2nd student's rate of working:
( 1 job ) / ( 20 min )
Let +t+ = time in minutes for them
to do the job working together
---------------------------
Add their rates of working to get their rate
working together
+1%2F10+%2B+1%2F20+=+1%2Ft+
Multiply both sides by +20t+
+2t+%2B+t+=+20+
+3t+=+20+
+t+=+6.667+ min
Convert +.667+ min to seconds
+.667%2A60+=+40+ sec
-------------------
Working together, they finish the job
in 6 min 40 sec