document.write( "Question 1189020: 1. Train A has a speed 20 miles per hour greater than that of train B. If train A travels 300 miles in the same times train B travels 220 miles, what are the speeds of the two trains?\r
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document.write( "2. A woman has a total of $13,000 to invest. She invests part of the money in an account that pays 11% per year and the rest in an account that pays 12% per year. If the interest earned in the first year is $1490 how much did she invest in each account?
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Algebra.Com's Answer #820248 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! 1. The difference in speeds of the two trains is 20mph; the difference in distances over the same amount of time is 80 miles. So the time traveled is 80/20 = 4 hours. \n" ); document.write( "Train A travels 300 miles in 4 hours, a speed of 75mph; train B travels 220 miles in 4 hours, a speed of 55mph. \n" ); document.write( "ANSWERS: 75 and 55mph \n" ); document.write( "2. Here is an informal method for solving \"mixture\" problems like this that is nearly always faster and easier than the standard formal algebraic method shown by the other tutor. \n" ); document.write( "(a) All $13,000 invested at 11% would yield $1430 interest; all invested at 12% would yield $1560 interest. \n" ); document.write( "(b) View the three interest amounts $1430, $1490, and $1560 on a number line and observe/calculate that $1490 is $60/$130 = 6/13 of the way from $1430 to $1560. \n" ); document.write( "(c) That means 6/13 of the total was invested at the higher rate. \n" ); document.write( "6/13 of $13,000 is $6000, so \n" ); document.write( "ANSWERS: $6000 invested at 12%, the other $7000 at 11% \n" ); document.write( "CHECK: .12(6000)+.11(7000) =720+770=1490 \n" ); document.write( " \n" ); document.write( " |