document.write( "Question 286464: Juan left home on his bicycle at 10:00 a.m. traveling at 21 km/h. At noon, his brother set out after him on his motorcycle following the same route. If the motorcycle traveled at 63 km/h, what time did Juan's brother overtake him?\r
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document.write( "Thank you, sir \n" );
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Algebra.Com's Answer #207796 by PRMath(133)![]() ![]() ![]() You can put this solution on YOUR website! Juan left home on his bicycle at 10:00 a.m. traveling at 21 km/h. At noon, his brother set out after him on his motorcycle following the same route. If the motorcycle traveled at 63 km/h, what time did Juan's brother overtake him? \n" ); document.write( "Thank you, sir\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "You just need to think of the importance of this equation: \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "In other words, RATE times TIME equals DISTANCE.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now....with that info, make a little chart for yourself:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "________RATE_______TIME______DISTANCE_________\r \n" ); document.write( "\n" ); document.write( "Juan..............21.........................T............................D............\r \n" ); document.write( "\n" ); document.write( "Brother........63.........................T -2......................D............\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "See, the brother started out two hours behind Juan, or T - 2. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Also, when the brother overtakes Juan, then that means they will be at the exact same place, or the exact distance from the starting point. In other words: The distance for Juan equals the distance for the Brother.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Knowing that they have to be at the same distance means that you set up an \n" ); document.write( "equation of: Distance = Distance (Or D = D)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "SO... let's say: \r \n" ); document.write( "\n" ); document.write( "D = D What does \"D\" equal? \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\"D\" equals RATE times TIME. \n" ); document.write( "For Juan, the RATE times TIME is: 21(T). \n" ); document.write( "For the brother the RATE times TIME is 63(T - 2)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's fill in that info:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "D = D \n" ); document.write( "21(T) = 63(T - 2) Now let's distribute the 63 to the T and 63 to the -2. \n" ); document.write( "21T = 63T - 126 Now let's subtract 63T from both sides to get the T variables on one side. \n" ); document.write( "21T - 63T = -126 Now let's subtract: 21T - 63T which is: -42T \n" ); document.write( "-42T = -126 Now divide both sides by -42 to further isolate the T. \n" ); document.write( "T = 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now if T equals 3 hours, let's see how that works:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Juan is traveling 21 kmp. In three hours that's: \n" ); document.write( "21(T) which is \n" ); document.write( "21(3) = 63 Kilometers.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The brother is traveling 63 kmp. In T - 2 hours that's: \n" ); document.write( "T - 2 which is 3 -2 = 1 \n" ); document.write( "63(1) = 63 Kilometers.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "SOoo in 1 hour, the brother will be at the 63 kilometer mark. Since the brother took off at noon, in 1 hour it will be 1 pm. It will also be 1 pm for Juan if he travels for 3 hours from 10 a.m. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I hope this helps you. And a \"sir\" did not answer your question. :-) A girl did. :-) Sometimes math types are girls, too. \r \n" ); document.write( "\n" ); document.write( "Good luck with your math. \n" ); document.write( " |