document.write( "Question 58898: Bike Rides - Jo and Chris set out together. they rode their bikes from a to b, from b to c and from c back to a. A to B = 4 miles, B to C = 4 miles, C to A = 4 miles.\r
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document.write( "jo rode at a constant speed all the way.
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document.write( "Chris rode from a to b at double jo's speed.
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document.write( "She rode from b to c at the same speed as jo
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document.write( "She rode from c back to a at half jo's speed.\r
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document.write( "Who got back to a first?
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document.write( "How far a head was she? \n" );
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Algebra.Com's Answer #40397 by uma(370)![]() ![]() ![]() You can put this solution on YOUR website! Let Jo's speed be xmph \n" ); document.write( "Total distance travelled by Jo = 12 miles. \n" ); document.write( "So time taken by Jo = 12/x hrs\r \n" ); document.write( "\n" ); document.write( "Speed of Chris for travelling from A to B = 2x mph \n" ); document.write( "A to B = 4 miles \n" ); document.write( "So time taken = 4/2x \n" ); document.write( " = 2/x hrs\r \n" ); document.write( "\n" ); document.write( "Speed of Chris for travelling from B to C = x mph \n" ); document.write( "B to C = 4 miles \n" ); document.write( "So time taken = 4/x \n" ); document.write( " = 4/x hrs\r \n" ); document.write( "\n" ); document.write( "Speed of Chris for travelling from C to A = x/2 mph \n" ); document.write( "C to A = 4 miles \n" ); document.write( "So time taken = 4/(x/2) \n" ); document.write( " = 8/x hrs\r \n" ); document.write( "\n" ); document.write( "So total time taken = 2/x + 4/x + 8/x \n" ); document.write( " = 14/x hrs\r \n" ); document.write( "\n" ); document.write( "Comparing , we find that Jo reached A first as the time taken by her was only 12/x hrs\r \n" ); document.write( "\n" ); document.write( "Distance covered by Chris in 12/x hrs = (12/x)/ (14/x) * 12 \n" ); document.write( " = 10.3 miles\r \n" ); document.write( "\n" ); document.write( "So Jo is ahead of Chris by 12 - 10.3 = 1.7 miles\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |