document.write( "Question 244764: \"It took a faster runner 10 seconds longer to run a distance of 1500 feet than it took a slower runner to run a distance of 1000 feet. if the rate of the faster runner was 5 ft/s more than the rate of the slower runner, what was the rate of each?\" \n" ); document.write( "
Algebra.Com's Answer #178978 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! \"It took a faster runner 10 seconds longer to run a distance of 1500 feet than it took a slower runner to run a distance of 1000 feet. \n" ); document.write( "Let t = time in sec for the faster runner to run 1500 ft \n" ); document.write( "then \n" ); document.write( "(t-10) = time of the slower runner to run 1000 ft \n" ); document.write( ": \n" ); document.write( "if the rate of the faster runner was 5 ft/s more than the rate of the slower runner, what was the rate of each?\" \n" ); document.write( ": \n" ); document.write( "Write a rate equation: Rate = dist/time: \n" ); document.write( ": \n" ); document.write( "Fast rate - slow rate = 5 ft/sec \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "Multiply equation by t(t-10), results \n" ); document.write( "1500(t-10) - 1000t = 5t(t-10) \n" ); document.write( ": \n" ); document.write( "1500t - 15000 - 1000t = 5t^2 - 50t \n" ); document.write( ": \n" ); document.write( "500t - 15000 = 5t^2 - 50t \n" ); document.write( ": \n" ); document.write( "0 = 5t^2 - 50t - 500t + 15000 \n" ); document.write( "A quadratic equation \n" ); document.write( "5t^2 - 550t + 15000 = 0 \n" ); document.write( "Simplify, divide by 5 \n" ); document.write( "t^2 - 110t + 3000 = 0 \n" ); document.write( "Factor to \n" ); document.write( "(t - 50)(t - 60) = 0 \n" ); document.write( "two solutions \n" ); document.write( "t = 50 sec \n" ); document.write( "t = 60 sec \n" ); document.write( ": \n" ); document.write( "Assume t = 50 \n" ); document.write( "1500/50 = 30 ft/sec for the fast guy \n" ); document.write( "and \n" ); document.write( "1000/40 = 25 ft/sec for the slow guy (5 ft/sec slower) \n" ); document.write( ": \n" ); document.write( "You can check the other solution \n" ); document.write( " |