SOLUTION: Mary and Carol are doing a math project. Carol can do work twice as fast as Mary. If they work together they can finish the project in 4 hours. If they work together , what equati

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Mary and Carol are doing a math project. Carol can do work twice as fast as Mary. If they work together they can finish the project in 4 hours. If they work together , what equati      Log On


   

Question 888491: Mary and Carol are doing a math project. Carol can do work twice as fast as Mary. If they work together they can finish the project in 4 hours. If they work together , what equation would represent the amount of work they can finish in 1 hour
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +t+ = the time in hours for Mary to finish a project
So, Mary's rate of working is ( 1 project / t hrs )
Carol's rate of working is ( 1 project / t/2 hrs )
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Working together, their rate is ( 1 project / 4 hrs )
Add their individual rates of working to get rate working together
+1%2Ft+%2B+1%2F%28t%2F2%29+=+1%2F4+
+1%2Ft+%2B+2%2Ft+=+1%2F4+
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As for the amount of work they can finish in +1+ hr,
+1%2Ft+%2B+2%2Ft+=+%28%28+1%2F4+%29%29+%2F+1+