Respuesta :
Plug n = 18 and r = 6 into the nCr combination formula
n C r = (n!)/(r!*(n-r)!)
18 C 6 = (18!)/(6!*(18-6)!)
18 C 6 = (18!)/(6!*12!)
18 C 6 = (18*17*16*15*14*13*12!)/(6!*12!)
18 C 6 = (18*17*16*15*14*13)/(6!)
18 C 6 = (18*17*16*15*14*13)/(6*5*4*3*2*1)
18 C 6 = 13366080/720
18 C 6 = 18564
Answer: 18564
n C r = (n!)/(r!*(n-r)!)
18 C 6 = (18!)/(6!*(18-6)!)
18 C 6 = (18!)/(6!*12!)
18 C 6 = (18*17*16*15*14*13*12!)/(6!*12!)
18 C 6 = (18*17*16*15*14*13)/(6!)
18 C 6 = (18*17*16*15*14*13)/(6*5*4*3*2*1)
18 C 6 = 13366080/720
18 C 6 = 18564
Answer: 18564
