document.write( "Question 1069062: Alvin and Geraldine are addressing invitations to their wedding. Alvin can address one every thirteen seconds and Geraldine can do one in 40 seconds. how long will t take them to address 140 invitations? \n" ); document.write( "

Algebra.Com's Answer #684335 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
This is actually a \"work\" problem
\n" ); document.write( "Alvin's rate of working:
\n" ); document.write( "[ 1 invitation ] / [ 13 sec ]
\n" ); document.write( "Geraldine's rate of working:
\n" ); document.write( "[ 1 invitation ] / [ 40 sec ]\r
\n" ); document.write( "\n" ); document.write( "----------------------------
\n" ); document.write( "Let $\"+t+\"$ = time in sec to address
\n" ); document.write( "140 invitations
\n" ); document.write( "Their rate working together:
\n" ); document.write( "[ 140 invitations ] / [ t sec ]
\n" ); document.write( "---------------------
\n" ); document.write( "Add their rates of working to get their
\n" ); document.write( "rate working together
\n" ); document.write( " $\"+1%2F13+%2B+1%2F40+=+140%2Ft+\"$
\n" ); document.write( "Multiply both sides by $\"+13%2A40%2At+\"$
\n" ); document.write( " $\"+40t+%2B+13t+=+13%2A40%2A140+\"$
\n" ); document.write( " $\"+53t+=+72800+\"$
\n" ); document.write( " $\"+t+=+1373.58+\"$ sec
\n" ); document.write( "Convert this to minutes
\n" ); document.write( " $\"+1373.58+%2F+60+=+22.893+\"$ min
\n" ); document.write( "Convert the decimal part to seconds
\n" ); document.write( " $\"+.893%2A60+=+54+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "It will takes them 22 min 54 sec\r
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