Question 884205
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1.) 15p4 = start with 15 come down 4 factors: 15*14*13*12 = 32760   
2.) 9p3 = start with 9, come down 3 factors: 9*8*7 = 504
3.) 10c4 = NUMERATOR = start with 10 come down 4 factors
           DENOMINATOR = start with 4 come down 4 factors = {{{(10*9*8*7)/(4*3*2*1)}}} = cancel and multiply = 210

Edwin</pre>