document.write( "Question 373857: An airline leaves Phoenix traveling at an average rate of 420 mph. Thirty minutes later, a second airliner leaves phoenix traveling along a parallel route. If the second plane overtakes the first at a point 1680 miles from phoenix, find its rate. The difference in times is 30 min. \n" ); document.write( "

Algebra.Com's Answer #266052 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Both planes have traveled the same distance when they meet
\n" ); document.write( "which is 1680 mi
\n" ); document.write( "given:
\n" ); document.write( "1st plane:
\n" ); document.write( " $\"d+=+r%2At\"$
\n" ); document.write( "(1) $\"1680+=+420%2At\"$
\n" ); document.write( "2nd plane:
\n" ); document.write( " $\"1680+=+r%2A%28t+-.5%29\"$
\n" ); document.write( "(2) $\"1680+=+r%2At+-+.5r\"$
\n" ); document.write( "From (1):
\n" ); document.write( " $\"t+=+1680%2F420\"$
\n" ); document.write( " $\"t+=+4\"$
\n" ); document.write( "(2) $\"1680+=+4r+-+.5r\"$
\n" ); document.write( " $\"r%2A%284+-+.5%29+=+1680\"$
\n" ); document.write( " $\"r+=+%282%2F7%29%2A1680\"$
\n" ); document.write( " $\"r+=+480\"$
\n" ); document.write( "The 2nd plane's rate is 480 mi/hr \n" ); document.write( "

\n" );