document.write( "Question 158868: The speed of train A is 16 mph slower than the speed of train B. Train A travels 220 miles in the same time it takes train B to travel 300 miles. Find the speed of each train. \n" ); document.write( "
Algebra.Com's Answer #117020 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! rate * time = distance \n" ); document.write( "train A travels 16 mph slower than train B. if rate of train A is x miles per hour, then rate of train B is (x+16) miles per hour. \n" ); document.write( "let T = time in hours, \n" ); document.write( "if A travels 220 miles in T hours, then x*T = 220. \n" ); document.write( "if B travels 300 miles in T hours, then (x+16)*T = 300. \n" ); document.write( "solving for T, we get \n" ); document.write( "T = 220/x from the first equation, and \n" ); document.write( "T = 300/(x+16) from the second equation. \n" ); document.write( "since both equations equal T, they must be equal to each other, so \n" ); document.write( "220/x = 300/(x+16) \n" ); document.write( "solving for x, we multiply both sides of the equation by x*(x+16) to remove the denominators. equation becomes \n" ); document.write( "220*(x+16) = 300*x \n" ); document.write( "this becomes \n" ); document.write( "220*x + 220*16 = 300*x \n" ); document.write( "subtracting 220*x from both sides of the equations gets \n" ); document.write( "220*16 = 300*x - 220*x \n" ); document.write( "this becomes \n" ); document.write( "3520 = 80*x \n" ); document.write( "which becomes \n" ); document.write( "x = 44 mph \n" ); document.write( "it looks like train A is traveling 44 mph and train B is traveling 60 mph. \n" ); document.write( "once we know this we can solve for T. \n" ); document.write( "for train A, T = 220/44 = 5 hours \n" ); document.write( "for train B, T = 300/60 = 5 hours \n" ); document.write( "60 mph minus 44 mph = 16 mph so train B is traveling 16 mph faster than train A. \n" ); document.write( "answer checks out, so answer is: \n" ); document.write( "train A is traveling at 44 mph. \n" ); document.write( "train B is traveling at 16 mph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |