document.write( "Question 178125: A car travels 40 mph for 20 miles, 36 mph for 24 miles, and 48 mph for 16 miles. what is its average speed? \n" ); document.write( "
Algebra.Com's Answer #133060 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
The average speed is NOT the average of the averages
\n" ); document.write( "The average speed is (total distance)/(total time)
\n" ); document.write( "For the 3 parts od the trip,
\n" ); document.write( "(1) \"d%5B1%5D+=+r%5B1%5D%2At%5B1%5D\"
\n" ); document.write( "(2) \"d%5B2%5D+=+r%5B2%5D%2At%5B2%5D\"
\n" ); document.write( "(3) \"d%5B3%5D+=+r%5B3%5D%2At%5B3%5D\"
\n" ); document.write( "given:
\n" ); document.write( "(1) \"20+=+40%2At%5B1%5D\"
\n" ); document.write( "(2) \"24+=+36%2At%5B2%5D\"
\n" ); document.write( "(3) \"16+=+48%2At%5B3%5D\"
\n" ); document.write( "----------------------
\n" ); document.write( "\"t%5B1%5D+=+1%2F2\"
\n" ); document.write( "\"t%5B2%5D+=+2%2F3\"
\n" ); document.write( "\"t%5B3%5D+=+1%2F3\"
\n" ); document.write( "\"t%5B1%5D+%2B+t%5B2%5D+%2B+t%5B3%5D+=+1%2F2+%2B+2%2F3+%2B+1%2F3\"
\n" ); document.write( "\"t%5Bsum%5D+=+3%2F6+%2B+4%2F6+%2B+2%2F6\"
\n" ); document.write( "\"t%5Bsum%5D+=+9%2F6\"
\n" ); document.write( "\"t%5Bsum%5D+=+3%2F2\" hrs
\n" ); document.write( "and
\n" ); document.write( "\"d%5B1%5D+%2B+d%5B2%5D+%2B+d%5B3%5D+=+20+%2B+24+%2B+16\"
\n" ); document.write( "\"d%5Bsum%5D+=+60\"
\n" ); document.write( "Average speed = \"d%5Bsum%5D%2Ft%5Bsum%5D+=+60%2F%283%2F2%29\"
\n" ); document.write( "\"60%2F%283%2F2%29+=+%282%2F3%29%2A60\"
\n" ); document.write( "\"%282%2F3%29%2A60+=+40\" mi/hr answer
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