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document.write( "Ling lives 2 miles from school. It took him 15 minutes to bike from school to home. The first half of the distance
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document.write( "he biked at a speed of 12 mph. What was his speed for the remaining distance? What was his average speed?
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document.write( "\"the first half of the distance he biked at a speed of 12 mph\".\r\n" );
document.write( "So, Ling biked 1 miles at the speed of 12 mph = 
= 0.2 miles per minute. \r\n" );
document.write( "Thus Ling spent 
= 5 minute to cover the first half of the distance.\r\n" );
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document.write( "For the second half, which is also 1 mile, Ling spent the remaining 15-5 = 10 minutes, i.e. twice the time he spent for the first mile. \r\n" );
document.write( "It means that his speed was half of the speed on the first mile, 
= 6 mph.\r\n" );
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document.write( "It is the answer to the first question.\r\n" );
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document.write( "Regarding the average speed, it is the FULL distance divided by the FULL time, i.e. 
= 
= 2*4 = 8 mph. \r\n" );
document.write( "(Here 
is 15 minutes = 1/4 of an hour.)\r\n" );
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document.write( "Answer. The Ling's speed on the second half of the distance was 6 mph.\r\n" );
document.write( " The average speed was 8 mph.\r\n" );
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document.write( "The solution by jorel555 is wrong in this part.\r\n" );
document.write( "The error he made is TYPICAL and represents the good/classic example on how this problem SHOULD NOT be solved. \r\n" );
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