SOLUTION: A technician and his assistant can repair a bus in 9 hours. The technician works 4 times as fast as his assistant. How long would it take the assistant to repair the bus alone?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A technician and his assistant can repair a bus in 9 hours. The technician works 4 times as fast as his assistant. How long would it take the assistant to repair the bus alone?      Log On


   

Question 733605: A technician and his assistant can repair a bus in 9 hours. The technician works 4 times as fast as his assistant. How long would it take the assistant to repair the bus alone?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Their rate working together is ( 1 bus repaired ) / ( 9 hrs )
Let +r+ = the rate the assistant works
+4r+ = the rate the technician works
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+r+%2B+4r+=+1%2F9+
+5r+=+1%2F9+
+r+=+1%2F45+
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The assistant takes 45 hrs working alone
check:
+1%2F45+%2B+4%2F45+=+5%2F45+
+5%2F45+=+5%2F45+
OK