document.write( "Question 143667: I am having a lot of trouble with word problem questions. If someone could help me that would be great. If you could show your work so that I can understand how you got the answer would be apprectiated. Thanks so much!\r
\n" );
document.write( "\n" );
document.write( "*In a certain medical test designed to measure carbohydrate tolerance, and adult drinks 7 ounces of a 30% glucose solution. When the test is administered to a child, the glucose concentration must be decreased to 20%. How much 30% glucose solution and how much water should be used to prepare 7 ounces of 20% glucose solution?\r
\n" );
document.write( "\n" );
document.write( "*Theophylline, is prepared from an elixir with a drug concentration of 5 mg/ml and a cherry-flavored syrup that is to be added to hide the taste of the drug. How much of each must be used tp prepare 100 mililiters of solution with a drug concentratio of 2 mg/ml?\r
\n" );
document.write( "\n" );
document.write( "*Two children who are 224 meters apart, start walking toward each other at the same instant at rates of 1.5m/sec and 2 m/sec, respectively.
\n" );
document.write( "(a) When will they meet?
\n" );
document.write( "(b) How far will each have walked?\r
\n" );
document.write( "\n" );
document.write( "*A wafer cone is to hold 8 in^3 of ice cream when filled to the bottom. The diameter of the cone is 2 inches, and the top of the ice cream has the shape of a hemisphere. Find the height (h) of the cone.\r
\n" );
document.write( "\n" );
document.write( "*A runner starts at the beginning of a runners' path and runs at a constant rate of 6 mi/hr. Five minutes later a second runner begins at the same point, running at a rate of 8 mi/hr and following the same course. How long will it take the second runner to reach the first? \n" );
document.write( "
Algebra.Com's Answer #104554 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! In a certain medical test designed to measure carbohydrate tolerance, and adult drinks 7 ounces of a 30% glucose solution. When the test is administered to a child, the glucose concentration must be decreased to 20%. How much 30% glucose solution and how much water should be used to prepare 7 ounces of 20% glucose solution? \n" ); document.write( ": \n" ); document.write( "Let x = amt of 30% glucose solution \n" ); document.write( "We want the resulting total to be 7 oz, therefore \n" ); document.write( "(7-x) = amt of water required (water is a 0% solution) \n" ); document.write( ": \n" ); document.write( "A percent glucose equation. \n" ); document.write( ": \n" ); document.write( "The amt of glucose remains the same, (the percent changes by adding water) \n" ); document.write( ": \n" ); document.write( ".30x = .20(7) \n" ); document.write( ".3x = 1.4 \n" ); document.write( "x = \n" ); document.write( "x = 4 \n" ); document.write( "then \n" ); document.write( "7 - 4 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "*Theophylline, is prepared from an elixir with a drug concentration of 5 mg/ml and a cherry-flavored syrup that is to be added to hide the taste of the drug. How much of each must be used to prepare 100 milliliters of solution with a drug concentration of 2 mg/ml? \n" ); document.write( ": \n" ); document.write( "Let x = amt of 5 mg elixir required \n" ); document.write( "then \n" ); document.write( "(100-x) = amt of syrup required \n" ); document.write( ": \n" ); document.write( "5x = 2(100) \n" ); document.write( "5x = 200 \n" ); document.write( "x = \n" ); document.write( "x = 40 ml of elixir \n" ); document.write( "then \n" ); document.write( "100-40 = 60 ml of syrup \n" ); document.write( ": \n" ); document.write( "; \n" ); document.write( "*Two children who are 224 meters apart, start walking toward each other at the same instant at rates of 1.5m/sec and 2 m/sec, respectively. \n" ); document.write( ": \n" ); document.write( "The total distance of both will equal 224 meters. Write a distance equation: \n" ); document.write( "Dist = speed * time \n" ); document.write( ": \n" ); document.write( "(a) When will they meet? \n" ); document.write( "Let t = time (in sec) when they meet: \n" ); document.write( "; \n" ); document.write( "child 1 dist + child 2 dist = 224 meters \n" ); document.write( "1.5t + 2t = 224 \n" ); document.write( "3.5t = 224 \n" ); document.write( "t = \n" ); document.write( "t = 64 seconds \n" ); document.write( ": \n" ); document.write( "(b) How far will each have walked? \n" ); document.write( "now we know t \n" ); document.write( "1.5*64 = 96 meters (child 1) \n" ); document.write( "2.0*64 = 128 meters (child 2) \n" ); document.write( "-------------- \n" ); document.write( "total = 224, confirms our solution \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "*A wafer cone is to hold 8 in^3 of ice cream when filled to the bottom. The diameter of the cone is 2 inches, and the top of the ice cream has the shape of a hemisphere. Find the height (h) of the cone. \n" ); document.write( ": \n" ); document.write( "The vol of a cone + the vol of half sphere = 8 cu in \n" ); document.write( "r=1 in (half the diameter \n" ); document.write( " \n" ); document.write( "using the given values for r \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( "Use a calc \n" ); document.write( "1.0472h + 1.5708 = 8 \n" ); document.write( ": \n" ); document.write( "1.0472h = 8 - 1.5708 \n" ); document.write( ": \n" ); document.write( "1.0472h = 6.4292 \n" ); document.write( "h = \n" ); document.write( "h = 6.14 inches the height of the cone part only, the part including hemisphere would be an inch higher, 7.14\" \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "*A runner starts at the beginning of a runners' path and runs at a constant rate of 6 mi/hr. Five minutes later a second runner begins at the same point, running at a rate of 8 mi/hr and following the same course. How long will it take the second runner to reach the first? \n" ); document.write( "; \n" ); document.write( "We know that when the 2nd runner catches up with the 1st, they will have run the same distance. \n" ); document.write( ": \n" ); document.write( "Change 5 min to hrs: 5/60 = 1/12 \n" ); document.write( ": \n" ); document.write( "Let t = run time of the 2nd runner \n" ); document.write( "then \n" ); document.write( "(t+ \n" ); document.write( ": \n" ); document.write( "Write a dist equation: Dist = speed * time \n" ); document.write( ": \n" ); document.write( "Fast runner dist = slow runner dist \n" ); document.write( "8t = 6(t+ \n" ); document.write( "8t = 6t + \n" ); document.write( "8t - 6t - \n" ); document.write( "2t = \n" ); document.write( "t = \n" ); document.write( "t = \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "We can check solution by finding the distance traveled by each runner (should be equal) \n" ); document.write( "1st runners time = 20 min, 2nd runner 15 min \n" ); document.write( "6 * (20/60) = 2 mi \n" ); document.write( "8 * (15/60) = 2 mi \n" ); document.write( ": \n" ); document.write( "Hope you can follow all this, you can ask me about it until 9:15 central daylight or tomorrow. ankor@dixie-net.com\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |