document.write( "Question 76661: Ed and Dave are going to divide a case prize of $14,000 in a ratio of 2 to 5. How much will Dave receive?\r
\n" ); document.write( "\n" ); document.write( "I came up with 8,000. I am not sure this is correct. Could you verify this for me? Thanks.
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Algebra.Com's Answer #54983 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
Well, let's see.
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\n" ); document.write( "The total prize is $14,000. Let's call Dave's share D and Ed's share E. The sum of the two
\n" ); document.write( "shares has to total the entire prize. So we can write the equation:
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\n" ); document.write( "D + E = 14,000
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\n" ); document.write( "And by subtracting D from both sides of this equation we can see that Ed's share is:
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\n" ); document.write( "E = 14,000 - D
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\n" ); document.write( "So we can set up the ratio of Ed's share (14,000 - D) to Dave's share (D) and get:
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\n" ); document.write( "\"E%2FD+=+%2814000+-+D%29%2FD+\"
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\n" ); document.write( "but the problem also tells us that this ratio is \"2%2F5\"
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\n" ); document.write( "So we can set up the equation:
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\n" ); document.write( "\"%2814000+-+D%29%2FD+=+2%2F5\"
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\n" ); document.write( "When you have two ratios equal to each other, a method of solving them is to find the
\n" ); document.write( "cross products and set them equal. The cross products come from multiplying the numerator of
\n" ); document.write( "one ratio times the denominator of the other ratio. Then multiply the denominator of
\n" ); document.write( "the first ratio times the numerator of the second ratio.
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\n" ); document.write( "In this problem the first cross product is
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\n" ); document.write( "\"%2814000+-+D%29%2A+5\" <--- numerator of first ratio times denominator of second
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\n" ); document.write( "and this multiplication results in \"70000+-+5%2AD\".
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\n" ); document.write( "and the second cross product is the denominator of the first ratio (D) times the numerator of
\n" ); document.write( "the second ratio (2) to get \"+2%2AD\".
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\n" ); document.write( "[You may be able to see why they are often referred to as cross products. You are multiplying
\n" ); document.write( "along diagonals drawn through the equal sign between the two ratios.]
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\n" ); document.write( "Anyhow, set the two cross products equal and you get:
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\n" ); document.write( "\"70000+-+5%2AD+=+2%2AD\"
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\n" ); document.write( "Solve by adding \"5%2AD\" to both sides to eliminate the \"-5%2AD\" on the left side. This
\n" ); document.write( "results in:
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\n" ); document.write( "\"70000+=+7%2AD\"
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\n" ); document.write( "Solve for Dave's share by dividing both sides by 7 to get:
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\n" ); document.write( "\"+10000+=+D\"
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\n" ); document.write( "So Dave gets $10,000 which means that Ed gets the remaining $4,000 of the prize.
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\n" ); document.write( "Now check to see that the ratio is correct. Ask yourself, is $4,000 divided by $10,000
\n" ); document.write( "the same as \"2%2F5\"? If you divide both the numerator and the denominator by 2,000 you
\n" ); document.write( "find that \"4000%2F10000\" does, in fact, reduce to \"2%2F5\". Therefore, our answer is
\n" ); document.write( "correct.
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\n" ); document.write( "If you do the same verification with your answer in which Dave got $8000 and Ed got the
\n" ); document.write( "remaining $6000 your ratio is \"6000%2F8000\" which is \"6%2F8\" and that reduces to
\n" ); document.write( "\"3%2F4\" not \"2%2F5\" as required by the problem.
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\n" ); document.write( "Hope this helps you to see your way through the problem and perhaps introduces you to
\n" ); document.write( "using cross products to solve proportions (two ratios set equal).
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