document.write( "Question 763148: man A set out from a certain point and travelled at the rate of 6 kph. After A had gone 2 hrs, another man B set out to overtake him and went 4km the 1st hour, 5km for the second hour, 6 km for the 3rd hour and so on gaining 1 km every hour. After how many hours will they be together? \n" ); document.write( "
Algebra.Com's Answer #464651 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! man A set out from a certain point and travelled at the rate of 6 kph. \n" ); document.write( " After A had gone 2 hrs, another man B set out to overtake him and \n" ); document.write( " went 4km the 1st hour, 5km for the second hour, 6 km for the 3rd hour \n" ); document.write( " and so on gaining 1 km every hour. \n" ); document.write( "After how many hours will they be together? \n" ); document.write( "; \n" ); document.write( "We know from the information given, that Man A has traveled 12 km when \n" ); document.write( "Man B starts after him. \n" ); document.write( ": \n" ); document.write( "Let x = no. of hrs for B to catch A \n" ); document.write( "x also = no. of km added to 4 km by the man B after x hrs \n" ); document.write( ": \n" ); document.write( "B's dist = A's dist \n" ); document.write( "x( \n" ); document.write( " \n" ); document.write( "multiply both sides by 2 \n" ); document.write( "x^2 - x + 8x = 12x + 24 \n" ); document.write( "combine like terms on the left \n" ); document.write( "x^2 - x + 8x - 12x - 24 = 0 \n" ); document.write( "x^2 - 5x - 24 = 0 \n" ); document.write( "Factors to: \n" ); document.write( "(x-8)(x+3) = 0 \n" ); document.write( "The positive solution \n" ); document.write( "x = 8 hrs from the time B starts,they are together \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Prove this by doing it the long way \n" ); document.write( "Hr_A___B (add one km each hr) \n" ); document.write( " 1 18 km, 4 km \n" ); document.write( " 2 24 km, 9 km, added 5 \n" ); document.write( " 3 30 km, 15 km, added 6 \n" ); document.write( " 4 36 km, 22 km, added 7 \n" ); document.write( " 5 42 km, 30 km, added 8 \n" ); document.write( " 6 48 km, 39 km, added 9 \n" ); document.write( " 7 54 km, 49 km, added 10 \n" ); document.write( " 8 60 km, 60 km, added 11, same distance after 8 hrs\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |