Question

1×2×3×...×2003×2004的积的末尾共有（ ）连续的0

Answer 1

5,10,…,2000,

相乘 =5^400*(1*2*...*400)

(1,2,...400)相乘= 5*10*...*400=5^80*(1*2*3*...*80)

(1*2*3*...*80)相乘=5*10*...*80=5^16*(1*2*...*16)=5^16+5^3=5^19

400+80+16+3=499