document.write( "Question 983903: Hi a and b had a total of 27 coins.when a gave 1/4 of his coins to b b had twice as many cojns as
\n" ); document.write( "a .b then found out that she had twice as many 20cent coins as 10 cent coins.how much money
\n" ); document.write( "did b have in the end.\r
\n" ); document.write( "\n" ); document.write( "thank you
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Algebra.Com's Answer #604734 by KMST(5328)\"\" \"About 
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\"a\"= number of coins a initially had.
\n" ); document.write( "\"b\"= number of coins b initially had.
\n" ); document.write( "You can find \"a\" and \"b\" by
\n" ); document.write( "solving a system of equations, or by
\n" ); document.write( "guess and check.
\n" ); document.write( "From there, you can figure out how many coins b has in the end.
\n" ); document.write( "Knowing how many coins b has in the end,
\n" ); document.write( "and knowing that some of those coins are 10 cent coins,
\n" ); document.write( "and the rest are 20 cent coins,
\n" ); document.write( "with twice as many 20 cent coins as 10 cent coins,
\n" ); document.write( "you can figure out how many coins of each kind b has in the end.
\n" ); document.write( "Knowing how many coins of each kind b has in the end, you can figure out how much money those coins amount to.\r
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\n" ); document.write( "\n" ); document.write( "THE ALGEBRA WAY:
\n" ); document.write( "\"a%2Bb=27\" because initially a and b had a total of 27 coins.
\n" ); document.write( "\"%281%2F4%29a=0.25a\"= number of coins a gave to b.
\n" ); document.write( "\"a-0.25a=0.75a\"= number of coins a had in the end.
\n" ); document.write( "\"0.25a%2Bb\"= number of coins b had in the end.
\n" ); document.write( "\"2%280.75a%29=0.25a%2Bb\" because in the end b had twice as many coins as
\n" ); document.write( "a.
\n" ); document.write( "\"2%280.75a%29=0.25a%2Bb\"-->\"1.5a=0.25a%2Bb\"-->\"1.5a-0.25a=b\"-->\"%281.5-0.25%29a=b\"-->\"1.25a=b\"
\n" ); document.write( "\"system%281.25a=b%2Ca%2Bb=27%29\"--->\"system%281.25a=b%2Ca%2B1.25a=27%29\"--->\"system%281.25a=b%2C2.25a=27%29\"--->\"system%281.25a=b%2Ca=27%2F2.25%29\"--->\"system%281.25a=b%2Ca=12%29\"--->\"system%281.25%2A12=b%2Ca=12%29\"--->\"system%2815=b%2Ca=12%29\"
\n" ); document.write( "So, \"0.25a%2Bb=0.25%2A12%2A15=3%2B15=18\"= total number of coins b had in the end.
\n" ); document.write( "= total number of coins b had in the end.
\n" ); document.write( "\"3x=18\"-->\"x=18%2F3\"--->\"x=6\"--->\"2x=2%2A6=12\"
\n" ); document.write( "\"6%2A%28%22%240.10%22%29=%22%240.60%22\" = value of \"6\" 10-cent coins.
\n" ); document.write( "\"12%2A%28%22%240.20%22%29=%22%242.40%22\" = value of \"12\" 20-cent coins.
\n" ); document.write( "\"%22%240.60%22%2B%22%242.40%22=highlight%28%22%243.00%22%29\"= total value of the \"6\" 10-cent coins and \"12\" 20-cent coins b had in the end.\r
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\n" ); document.write( "\n" ); document.write( "THE \"GUESS-AND-CHECK\" WAY:
\n" ); document.write( "Since a and b initially had a total of 27 coins, and a gave 1/4 of his coins to b,
\n" ); document.write( "initially a must have had a number of coins that divides by 4 evenly, and is less than 27,
\n" ); document.write( "such as 4, or 8, or 12, or 16, or 20, or 24.
\n" ); document.write( "If it was 4, b would have initially had 27-4=23 coins;
\n" ); document.write( "a would have given b just 1 coin, keeping the other 4-1=3 coins,
\n" ); document.write( "and b would have had 23+3=26 coins in the end.
\n" ); document.write( "Those 26 coins are a much greater number of coins than twice the 3 coins a had in the end.
\n" ); document.write( "So, b must have started with less than 23 coins and a must have started with more than 4 coins.
\n" ); document.write( "If a started with 8 coins, a would have given 2 of them to b, ending with 8-2=6 coins,
\n" ); document.write( "while b would have started with 27-8=19 coins, and would have ended with 19+2=21.
\n" ); document.write( "Those 21 coins are a greater number of coins than twice the 6 coins a had in the end.
\n" ); document.write( "So, a must have started with more than 8 coins.
\n" ); document.write( "If a started with 12 coins, a would have given 3 of them to b, ending with 12-3=9 coins,
\n" ); document.write( "while b would have started with 27-12=15 coins, and would have ended with 15+3=18,
\n" ); document.write( "which is twice as many coins as the 9 coins a ended up with.
\n" ); document.write( "So, a started with 12 coins, and b had 18 coins in the end.
\n" ); document.write( "Those 21 coins are a greater number of coins than twice the 6 coins a had in the end.
\n" ); document.write( "From there you can continue as above, or guess-and-check to find how many of those 18 coins are 10 cent coins.
\n" ); document.write( "If at the end just 1 of the coins b had was a 10-cent coin, b would have had 2 20-cent coins for a total of 1+2=3 coins.
\n" ); document.write( "So the number of 10-cent coins must b had in the end must have been more than 1.
\n" ); document.write( "If at the end just 5 of the coins b had were 10-cent coins, b would have had twice 5, or 10 20-cent coins for a total of 5+10=15 coins.
\n" ); document.write( "Since b had 18 coins at the end, and 18 is more than 15,
\n" ); document.write( "the number of 10-cent coins must b had in the end must have been more than 5.
\n" ); document.write( "If at the end 6 of the coins b had were 10-cent coins, b would have had twice 6, or 12 20-cent coins for a total of 6+12=18 coins.
\n" ); document.write( "Since b had 18 coins at the end, that is the mix of coins b had at the end,
\n" ); document.write( "and 6 10-cent coins plus 12 20-cent coins make $3.00.
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