Areteem: MCI-C Handout 3 Assignment

Online Course Discussion Forum

For number 3.20,

"What is the remainder of 1!+2!+3!+...+2016! upon division by 5?"

Can anyone help me to get started on this problem?

You could start by finding the remainder of $1!, 2!, 3!, 4!, 5!, 5!, 6!.\dots$ and try to spot a pattern of some sort.