anu1706 wrote:
But in this case !20+17 is not completely divisible by 17.So 17 is not the factor of sum of !20+17.Please clarify?
Actually it is:
20! + 17=17(1*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*18*19*20+1)
\frac{20! + 17}{17}=1*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*18*19*20+1
Hope it's clear.