document.write( "Question 763225: how many different combination can be made of the letters a,b,c,d,e,f,g,h taken 4 at a time \n" ); document.write( "
Algebra.Com's Answer #464623 by ramkikk66(644)\"\" \"About 
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4 letters can be chosen from 8 in \"8 choose 4\" or C(8,4) ways
\n" ); document.write( "which is given by the formula
\n" ); document.write( "(8*7*6*5)/(1*2*3*4) = 70 ways\r
\n" ); document.write( "\n" ); document.write( "For each of these selections, the set of 4 letters can be arranged in 4! = 24 ways.\r
\n" ); document.write( "\n" ); document.write( "Hence number of different combinations = 70*24 = 1680\r
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