document.write( "Question 760048: to a certain job A takes three times as long as B takes. if both of them working together take 9 days, how many days will a take to finish the job working alone? \n" ); document.write( "

Algebra.Com's Answer #462397 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let A's rate of working = $\"+R%5Ba%5D+\"$
\n" ); document.write( "B works 3 times faster, so
\n" ); document.write( "B's rate of working = $\"+3R%5Ba%5D+\"$
\n" ); document.write( "Their rate working together is ( 1 job ) / ( 9 days )
\n" ); document.write( "-------------
\n" ); document.write( "If you add their rates of working, you get
\n" ); document.write( "their rate working together
\n" ); document.write( " $\"+R%5Ba%5D+%2B+3R%5Ba%5D+=+1%2F9+\"$
\n" ); document.write( " $\"+4R%5Ba%5D+=+1%2F9+\"$
\n" ); document.write( " $\"+R%5Ba%5D+=+1%2F36+\"$
\n" ); document.write( " $\"+3R%5Ba%5D+=+3%2F36+\"$
\n" ); document.write( " $\"+3R%5Ba%5D+=+1%2F6+\"$
\n" ); document.write( "Working alone, A will finish the job in 36 days
\n" ); document.write( "check:
\n" ); document.write( " $\"+R%5Ba%5D+%2B+3R%5Ba%5D+=+1%2F9+\"$
\n" ); document.write( " $\"+1%2F36+%2B+3%2F36+=+1%2F9+\"$
\n" ); document.write( " $\"+4%2F36+=+1%2F9+\"$
\n" ); document.write( " $\"+1%2F9+=+1%2F9+\"$
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );