document.write( "Question 1083155: A student must leave for campus in 10 minutes or he will be late for class. Unfortunately, he is snowed in. He can shovel the driveway in 20 minutes, and his brother claims to be able to do it in 12 minutes. If they shovel together, how long will it take to clear the driveway? Will this give enough time for the student to get to the campus? \n" ); document.write( "

Algebra.Com's Answer #697163 by josmiceli(19441) $\"\"$ $\"About$

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Add their rates of shoveling to get their
\n" ); document.write( "rate shoveling together
\n" ); document.write( "student's rate:
\n" ); document.write( "[ 1 driveway shoveled / 20 min ]
\n" ); document.write( "brother's rate:
\n" ); document.write( "[ 1 driveway shoveled / 12 min ]
\n" ); document.write( "--------------------------------
\n" ); document.write( "Let $\"+t+\"$ = their time to shovel the
\n" ); document.write( "driveway working together
\n" ); document.write( " $\"+1%2F20+%2B+1%2F12+=+1%2Ft+\"$
\n" ); document.write( "Multiply both sides by $\"+60t+\"$
\n" ); document.write( " $\"+3t+%2B+5t++=+60+\"$
\n" ); document.write( " $\"+8t+=+60+\"$
\n" ); document.write( " $\"+t+=+7.5+\"$
\n" ); document.write( "They can shovel the driveway in 7.5 min, which
\n" ); document.write( "is less than 10 min needed
\n" ); document.write( " \n" ); document.write( "

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