document.write( "Question 840890: a sportsman covered 15km on a bicycle at a uniform speed.if he increased his speed by 2km/h, he would have derived at a destination 1/4 hour earlier. find the original speed? \n" ); document.write( "

Algebra.Com's Answer #506453 by hamsanash1981@gmail.com(151) $\"\"$ $\"About$

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Let he original speed be x and differenc in time is 1/4. then increase in speed by 2 will be x+2\r
\n" ); document.write( "\n" ); document.write( "time taken = distance / speed
\n" ); document.write( "original time taken = 15/x
\n" ); document.write( "time taken after increase in speed by 2 km/hr to cover the same distance = 15/x+2\r
\n" ); document.write( "\n" ); document.write( "difference in time = 1/4
\n" ); document.write( "15/x-15/(x+2)=1/4
\n" ); document.write( "(15(x+2) - 15x)/x(X+2) = 1/4
\n" ); document.write( "4(15(x+2-x)=x^2+2x
\n" ); document.write( "120 = x^2 +2x
\n" ); document.write( "x^2+2X -120 = 0
\n" ); document.write( "factorizing above equation we get
\n" ); document.write( "(x+12)(x-10)=0
\n" ); document.write( "X=-12 X=10
\n" ); document.write( "Negotiating negative we have x = 10\r
\n" ); document.write( "\n" ); document.write( "Therefore the original speed is 10 km/hr \n" ); document.write( "

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