document.write( "Question 80073: Tom can walk 3.5 miles per hour; how long will it take him to travel 3.6 kilometers? \n" ); document.write( "
Algebra.Com's Answer #57430 by Edwin McCravy(20055) $\"\"$ $\"About$
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document.write( "Tom can walk 3.5 miles per hour; how long will it \r\n" );
document.write( "take him to travel 3.6 kilometers?\r\n" );
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document.write( "3.5 mi\r\n" );
document.write( "------ \r\n" );
document.write( "   h\r\n" );
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document.write( "Multiply that by a fraction that equals 1, which has\r\n" );
document.write( "miles on the bottom to cancel out the miles on the top.\r\n" );
document.write( "We create such a fraction by using the fact that\r\n" );
document.write( "5280 ft = 1 mile\r\n" );
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document.write( "3.5 mi    5280 ft\r\n" );
document.write( "------ x -------- \r\n" );
document.write( "  h        1 mi\r\n" );
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document.write( "Multiply that by a fraction that equals 1, which has\r\n" );
document.write( "feet on the bottom to cancel out the feet on the top.\r\n" );
document.write( "We create such a fraction by using the fact that\r\n" );
document.write( "12 in = 1 ft\r\n" );
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document.write( "3.5 mi    5280 ft    12 in\r\n" );
document.write( "------ x -------- x -------- \r\n" );
document.write( "  h        1 mi       1 ft\r\n" );
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document.write( "Multiply that by a fraction that equals 1, which has\r\n" );
document.write( "inches on the bottom to cancel out the inches on the top.\r\n" );
document.write( "We create such a fraction by using the fact that\r\n" );
document.write( "1 in = 2.54 cm\r\n" );
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document.write( "3.5 mi    5280 ft    12 in      2.54 cm\r\n" );
document.write( "------ x -------- x -------- x --------- \r\n" );
document.write( "  h        1 mi       1 ft       1 in\r\n" );
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document.write( "Multiply that by a fraction that equals 1, which has\r\n" );
document.write( "cm on the bottom to cancel out the cm on the top.\r\n" );
document.write( "We create such a fraction by using the fact that\r\n" );
document.write( "100 cm = 1 m\r\n" );
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document.write( "3.5 mi    5280 ft    12 in      2.54 cm      1 m\r\n" );
document.write( "------ x -------- x -------- x --------- x -------- \r\n" );
document.write( "  h        1 mi       1 ft       1 in       100 cm\r\n" );
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document.write( "Multiply that by a fraction that equals 1, which has\r\n" );
document.write( "m on the bottom to cancel out the m on the top.\r\n" );
document.write( "We create such a fraction by using the fact that\r\n" );
document.write( "1000 m = 1 km\r\n" );
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document.write( "3.5 mi    5280 ft    12 in      2.54 cm      1 m        1 km     \r\n" );
document.write( "------ x -------- x -------- x --------- x -------- x -------- \r\n" );
document.write( "  h        1 mi       1 ft       1 in       100 cm     1000 m\r\n" );
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document.write( "Now cancel out all the units\r\n" );
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document.write( "3.5 mi    5280 ft    12 in      2.54 cm      1 m        1 km     \r\n" );
document.write( "------ x -------- x -------- x --------- x -------- x -------- \r\n" );
document.write( "  h        1 mi       1 ft       1 in       100 cm     1000 m\r\n" );
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document.write( "And we are left with just\r\n" );
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document.write( " (3.5)(5280)(12)(2.54)(1)(1) km      563270.4 km     5.632704 km\r\n" );
document.write( "--------------------------------  = ------------- = -------------\r\n" );
document.write( "       h(100)(1000)                  100000 h              h\r\n" );
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document.write( "So his rate = 5.63704 km/h\r\n" );
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document.write( "Since TIME = DISTANCE/RATE, his time to go 3.6 km =\r\n" );
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document.write( "           = 3.6/5.63704 = .6391246549 h or 38.34747929 minutes\r\n" );
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document.write( "or about 38 minutes 21 seconds.\r\n" );
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document.write( "Edwin
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