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You can put this solution on YOUR website!
\n" ); document.write( "The other tutors are using the combination formula.\r
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\n" ); document.write( "\n" ); document.write( "I'll show an example calculation.
\n" ); document.write( "C(n,r) = (n!)/(r!(n-r)!)
\n" ); document.write( "C(7,3) = (7!)/(3!*(7-3)!)
\n" ); document.write( "C(7,3) = (7!)/(3!*4!)
\n" ); document.write( "C(7,3) = (7*6*5*4!)/(3!*4!)
\n" ); document.write( "C(7,3) = (7*6*5)/(3!)
\n" ); document.write( "C(7,3) = (7*6*5)/(3*2*1)
\n" ); document.write( "C(7,3) = 210/6
\n" ); document.write( "C(7,3) = 35
\n" ); document.write( "This indicates there are 35 ways to select 3 ripe tomatoes from a pool of 7 ripe tomatoes, where order doesn't matter. This assumes that we can distinguish the tomatoes apart.
\n" ); document.write( "C(7,3) = 35 is equivalent to saying 7C3 = 35.\r
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\n" ); document.write( "\n" ); document.write( "Note that 35 is found in Pascal's Triangle. Locate the row that starts with \"1,7,...\"
\n" ); document.write( "In that row, move 3 spots to the right and you should land on 35. Specifically you should land on the first copy of 35.
\n" ); document.write( "n = 7 tells us which row to look at, while r = 3 tells us how far to move to the right.\r
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\n" ); document.write( "\n" ); document.write( "In GeoGebra, you would type ncr(7,3) to compute the combination value.
\n" ); document.write( "Many other online calculators can be used as well. Or you can use a spreadsheet.
\n" ); document.write( "If you want to use Desmos, then you would input nCr(7,3) where the C must be uppercase and everything else lowercase.
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