document.write( "Question 1201878: A BAG CONTAINS EIGHT CHIPS
\n" ); document.write( "NUMBERED 1 THROUGH 8. TWO CHIPS
\n" ); document.write( "ARE DRAWN RANDOMLY THE BAG AND
\n" ); document.write( "LAID DOWN IN THE ORDER THEY WERE
\n" ); document.write( "DRAWN. WHAT IS THE PROBABILITY
\n" ); document.write( "THAT THE 2-DIGIT NUMBER FORMED IS
\n" ); document.write( "DIVISIBLE BY 3?
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Algebra.Com's Answer #836427 by math_tutor2020(3817)\"\" \"About 
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\n" ); document.write( "Answer: 5/14
\n" ); document.write( "5/14 = 0.357143 approximately\r
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\n" ); document.write( "\n" ); document.write( "Explanation:\r
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\n" ); document.write( "\n" ); document.write( "If the chip labeled \"1\" is selected 1st, then here are the other possible choices for the 2nd chip: 2,3,4,5,6,7,8
\n" ); document.write( "Once the chip is selected, we don't put it back.\r
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\n" ); document.write( "\n" ); document.write( "Of those remaining choices only {2,5,8} will form a two digit number that starts with 1 and is a multiple of 3.
\n" ); document.write( "Those numbers being: 12, 15, 18
\n" ); document.write( "Notice the gap of 3 between adjacent terms.
\n" ); document.write( "Furthermore, notice the sum of the digits of any value gives 3 or a multiple of 3
\n" ); document.write( "1+2 = 3
\n" ); document.write( "1+5 = 6
\n" ); document.write( "1+8 = 9\r
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\n" ); document.write( "\n" ); document.write( "If \"2\" was chosen first, then we could have any of these as the 2nd selection {1,4,7}. Again note the gap of 3 between terms.
\n" ); document.write( "21 --> 2+1 = 3
\n" ); document.write( "24 --> 2+4 = 6
\n" ); document.write( "27 --> 2+7 = 9
\n" ); document.write( "That shows we have multiples of 3.\r
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\n" ); document.write( "\n" ); document.write( "This process is carried out for the remaining two digit numbers.
\n" ); document.write( "It might be faster to look at a multiplication table, or rely on your memorization of multiples of 3, to quickly get the values we want.
\n" ); document.write( "Keep in mind that
  • Repeat digits aren't allowed. Something like \"33\" won't work.
  • We can't form numbers with the digit \"0\" in them (this chip label does not exist). This will rule out something like \"30\".
  • We can't form numbers with the digit \"9\" in them (this chip label does not exist either). This rules out something like \"39\".
Here is the list of all two digit numbers that are multiples of 3, and that follow the criteria listed above
\n" ); document.write( "12, 15, 18, 21, 24, 27, 36, 42, 45, 48, 51, 54, 57, 63, 72, 75, 78, 81, 84, 87\r
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\n" ); document.write( "\n" ); document.write( "There are 20 items in that list
\n" ); document.write( "This is out of 8*7 = 56 different two digit numbers possible that follow the criteria mentioned earlier.\r
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\n" ); document.write( "\n" ); document.write( "20/56 = (4*5)/(4*14) = 5/14 is the final answer as a fraction.\r
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\n" ); document.write( "\n" ); document.write( "5/14 = 0.357143 approximately
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