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 == cancel and multiply = 210 Edwin