document.write( "Question 1065767: Out of the work man x and y,x is twice as good as y to perform the work assigned to them.If x can finish the assigned work in 40 days less than y,then in how many days they together can finish the work if they work together? \n" ); document.write( "
Algebra.Com's Answer #680940 by Theo(13342)![]() ![]() You can put this solution on YOUR website! x can finish the work in 40 days less than y. \n" ); document.write( "x works twice as fast as y, if i understood you correctly.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if we let z = the rate of y, then 2z = the rate of x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "rate * time = quantity of work produced.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "quantity of work produced = 1 job.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if we let q = the time it takes y to finish the work, then q - 40 is the time it takes x to finish the work.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when y works, the formula becomes z * q = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x works, the formula becomes 2z * (q-40) = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if we solve both of these formulas for z, we get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z = 1/q and z = 1/(2 * (q-40))\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get z = 1/q and z = 1/(2q-80)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this means that 1/q = 1/(2q-80)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "cross multiply to get 2q-80 = q\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract q from both sides of this equaiton to get q-80 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for q to get q = 80\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when y works, you get zq = 1 which becomes 80z = 1 which becomes z = 1/80.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x works, you get 2z(q-40) = 1 which becomes 2z(80-40) = 1 which becomes 2z*40 = 1 which becomes 2z = 1/40.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "remember now, that the rate of y is z and the rate of x is 2z.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the rate of x is 1/80 of the job in 1 day.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the rate of y is 1/40 of the job in 1 day.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when they work together, their rates are additive, so you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(1/80 + 1/40) * q = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "q in this case is the time it takes when they are working together.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get 3/80 * q = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for q to get q = 80/3 = 26 and 2/3 days.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your answer should be that they take 26 and 2/3 days to complete the job when they work together. if i understood your problem correctly.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x works alone, he takes 40 days to complete the job. \n" ); document.write( "when y works alone, he takes 80 days to complete the job.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x takes 40 days less than y to complete the job, so that part checks out.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the rate of x is 1/40 of the job in one day while the rate of y is 1/80 of the job in 1 day, so the rate of x is twice the rate of y, so that part checks out as well.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "i believe that 26 and 2/3 days to complete the job when they work together is the solution you are looking for.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |