document.write( "Question 1037381: josie can type 100 words in the same time that it take jane to type 75 word. if jane's typing rate is 8 words per minute less than that of josie's, find jane's typing rate \n" ); document.write( "
Algebra.Com's Answer #652053 by Theo(13342)![]() ![]() You can put this solution on YOUR website! let a = the typing rate of josie \n" ); document.write( "let b = the typing rate of jane \n" ); document.write( "let x = the time it takes for each of them to finish typing. \n" ); document.write( "this means that josie takes x minutes to type 100 words. \n" ); document.write( "this means that jane takes x minutes to type 75 words.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the general formula is rate * time = quantity.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "for josie, this equation becomes a * x = 100 \n" ); document.write( "for jane, this equation becomes b * x = 75\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve both equations for x and you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 100/a \n" ); document.write( "x = 75/b\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this means that 100/a = 75/b \n" ); document.write( "cross multiply to get 100b = 75a \n" ); document.write( "solve for b to get b = 75a/100 which simplifies to b = 3/4 * a\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are given that b = a - 8. \n" ); document.write( "replace b with a-8 in this equation to get a-8 = 3/4 * a \n" ); document.write( "add 8 to both sides of this equation and subtract 3/4 * a from both sides of this equation to get a - 3/4 * a = 8 \n" ); document.write( "simplify to get 1/4 * a = 8 \n" ); document.write( "multiply both sides of this equation by 4 to get a = 32.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since b = a-8, you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "a = 32 \n" ); document.write( "b = 24\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since b = jane's typing rate, your answer is that ....\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "jane's typing rate is 24 words per minute.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can confirm the answer is correct since they both took the same time.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "rate * time = quantity\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "for josie, this means 32 * time = 100. \n" ); document.write( "for jane, this means 24 * time = 75\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for time in each equation and you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "for josie, time = 100 / 32 = 25 / 8. \n" ); document.write( "for jane, time = 75 / 24 = 25 / 8.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the time is the same, confirming the solution is correct.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "there was another way to solve this as well.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "same setup.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ax = 100 \n" ); document.write( "bx = 75\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract the second equation from the first to get ax - bx = 25 \n" ); document.write( "factor out the x to get (a-b)x = 25 \n" ); document.write( "solve for x to get x = 25/(a-b)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are given that b = a-8. \n" ); document.write( "replace b in the equation to get x = 25/(a - (a-8)) \n" ); document.write( "simplify to get x = 25/8.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "now that you know the time, you can solve for a and b.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "a * 25/8 = 100 \n" ); document.write( "a * 25 = 8*100 \n" ); document.write( "a = 8*100/25 = 8*4 = 32\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "b * 25/8 = 75 \n" ); document.write( "b * 25 = 8*75 \n" ); document.write( "b = 8*75/25 = 8*3 = 24\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you get the same answer either way.\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( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |